If you have a cough, you're going to be dead before the end of the show.
This is usually accompanied by nasty amounts of Blood from the Mouth which is always a bad sign, even when there's no plausible reason for it. May also involve collapsing. The character will probably try to hide it and will usually succeed until they actually pass out. This trope is almost always carried out by the Ill Girl or the Littlest Cancer Patient.
In Western literature the trope was heavily influenced by the prevalence of tuberculosis, an infectious disease considered by many historians to be the greatest killer in human history - yes, even greater than malaria or plague. The symptoms of tuberculosis (also known as consumption, phthisis, TB, or the White Death) are identical to those of the Incurable Cough Of Death, but death would usually come far more slowly for the TB patient, at least in Real Life.
Thematically, the unnamed disease tends to act like pneumonia or tuberculosis, even in futuristic settings where those real diseases might be cured. Other times it's a hyped up version of unfortunately very real symptoms of chronically overworked people. In general, wider knowledge of medical conditions doesn't let writers be specific without slipping up.
Of course, in real life, people cough all the time from non-life-threatening causes, but those generally don't make for interesting stories. Think of this trope as the medical variant of Chekhov's Gun: if someone coughs in the first act, they better be dead by the third. note Ironically, Chekhov himself died of tuberculosis, which he contracted sometime in 1884, finally succumbing to it in 1904, after a good twenty years that are widely considered his most productive period as a writer. Note that Chekhov being a doctor had little to do with his unusually long lifespan after diagnosis: before streptomycin, there was no known effective treatment or cure for TB.
Compare Soap Opera Disease and Victorian Novel Disease. If the character insists that it's nothing, then it's Definitely Just a Cold. The trope may also lead to a Healthcare Motivation.
As this is a Death Trope, unmarked spoilers follow, though, really, the entire point of the trope is that the death isn't a spoiler to the Genre Savvy viewer, so as far as spoiler by definition tropes go, this is one of the safer ones. In any case, you have been warned.
The above mentioned Okita also makes quite a few appearances in fiction, complete with his famous sickness. In Bakumatsu Kikansetsu Irohanihoheto he is a frail looking spectre of a man, who sees a ghostly cat and wastes away while reminiscing with the hero and lamenting his sad fate. Then he dies.
Gintama has few of these too. Most of them happen during serious fights (and usually only bad guy dies afterwards), but there's actual example too. Since killing off Okita Sougo (a character loosely based on Okita Souji) would've completely messed up the comedic nature of the series, mangaka twisted things a bit - instead of Sougo having tuberculosis, it was his sister Mitsuba who suffered from illness... and she lasts for about two episodes. Among fans the arc is considered to be a big Tear Jerker.
In CLANNAD, Ill Girl Nagisa has an evidently non-lethal version of this. Until she gives birth, which complicates things a bit.
In After Story, One of the first signs that her and Tomoya's daughter Ushio inherited the already deceased Nagisa's illness is that she beings coughing profusely. It gets nastier for both father and daughter. And then better.
In Berserk, one character seen during the "Conviction" arc is a prostitute who appears to be dying of a severe venereal disease. She claims the inside of her mouth is swelling up and her legs are covered in sores. Berserk being Berserk, we see plenty of her body, and none of the symptoms she describes are visible. The only symptom we do see? A nasty cough.
Well, we do see her suffering from severe vaginal bleeding as well, so it isn't just a cough.
In Bleach Juushirou Ukitake subverts the death aspect.. sorta, with a particularly terrible, bloody cough from an unnamed illness he's had from childhood. As a noble-ranked shinigami, he was born in Soul Society (the afterlife) but spirits are still capable of dying and even breathe. Usually, he's either laid up in bed or his activities will be interrupted by a violent coughing fit that will lead to him coughing up blood. Fans popularly conclude he has tuberculosis but the story itself has never confirmed the nature of the disease only that he obtained it in childhood and the shock of being diagnosed with it turned his hairwhite.
We don't have any idea what killed Hisana Kuchiki aside from the fact it was some kind of sickness. She didn't survive the end of winter with it and the anime gave her an Incurable Cough Of Death to emphasise her weakening condition.
Uchiha Itachi of Naruto dies from one of these. Apparently, he had been keeping himself alive with all sorts of medicine so he could be killed by Sasuke. Then we find out why. On the whole, it comes off as a huge Tear Jerker.
There's also Kimimaro, who plays this completely straight, and Hayate who has a cough, but averts the death aspect by being sliced in half.
Hinata Hyuga nearly avoids this. She acquires exponential damage to her body's chakra system and heart from facing her cousin, Neji Hyuga, in the preliminaries. She is still feeling the affects of such a strain on her body that she breaks out in a violent coughing fit during the fight between Neji and Naruto a month later and subsequently passes out. Kiba Inuzuka finds an ANBU overlooking the final Chunin matches It's really Kabuto Yakushi in disguise and has him heal her with his medical ninjutsu.
Sai's "older brother" Shin also died from one of these before Danzo could force them to fight to the death.
Hayate also appears to have this, though he dies by other means.
So far, this is the only actual disease we've seen in-universe. And we don't even actually know what it is.
Papillion from Busou Renkin has such a cough, and escapes his inevitable death by becoming a homunculus. However, his transformation was incomplete, so though he has an immortal, super-human body, his illness wasn't cured like it should have been and his cough carried over.
In Bt X, Hokuto suffers from radiation poisoning, and is stated to have few months of life left He isn't planning to last that long.
In Code Geass R2, The Ace Li Xingke has a chronic Incurable Cough Of Death that also causes Blood from the Mouth every so often when he pushes himself or his Knightmare Frame too far. Despite having the disease, he survives to see the end of the series. Then again, he isn't seen in the big wedding portrait in the end...
He lives. Check the background during Ougi and Nunnally's handshake. That big ol' mech look familiar?
One problem: That's the ONLY thing that appears. Even when the Tianzi goes to the wedding, Xingke doesn't appear, which is strange for her devoted bodyguard. It's entirely possible that someone else is piloting it, whether they're as capable as Kallen and Suzaku, or simply using it on a lower setting.
In Chrono Crusade, Joshua Christopher suffers from this trope, until he accepts Chrono's horn from Aion and becomes part of the antagonist organization, the Sinners..
Hyatt in Excel♥Saga is constantly coughing up blood, collapsing, vomiting and dying (several times a chapter).
In the Fruits Basket manga, it is revealed that Tohru's father Kazuya died of a badly treated pneumonia.
Izumi Curtis in Fullmetal Alchemist does this, although she isn't the usual character type. And there's a darker reason for the cough than just illness. A failed attempt to transmute her stillborn infant son back to life caused the destruction of her internal reproductive organs. The hemorrhaging gets much worse during periods of extreme stress or guilt, causing her to cough up a truly frightening amount of blood. In spite of this, she still outlives nearly every major character while enduring heavy combat.
Hohenheim later cures her Incurable Cough Of Death. He cannot bring her organs back, but via an alchemical punch to the gut he can permanently stop the bleeding and the cough. Ironic, no?
Ed and Al's mom Trisha also succumbs to this; not to mention the deaths of homunculi, and whenever anyone sustains a serious torso wound… Aw heck, FMA is in love with this trope.
Averted in Gravitation where Yuki not only collapses as he also coughs blood in the process but manages to survive. The illness is blamed on stress (it might be ulcers) and just as mysteriously as it appeared it disappears. Ironically or not Shuichi assumes that his lover is about to die.
In G Gundam, the "elderly" (actually only 50) Master Asia is the greatest fighter in the world. His Kung Fu is stronger than everybody else's. He can effortlessly destroy Humongous Mecha using just his bare hands, or by swinging a piece of cloth at them. Basically the only one who's even worthy of thinking about fighting him is the main character... who happens to be his student. Yet when he turns against his boss, a weakling of a normal human, poor Master Asia is conveniently incapacitated by his Incurable Cough Of Death.
Somewhat subverted in Glass Mask, since Maya's mother, Haru does suffer from tuberculosis, but actually dies after being hit by a car.
Also, in the manga Gundam SEED Astray, a master swordsmith and swordsman named Un'no is also able to fight against Humongous Mecha on foot...though he uses a katana to do it, and "only" slices the barrels off their guns. His Incurable Cough Of Death actually is TB, which he dies from shortly after passing on his knowledge to Lowe Gear.
Integra Hellsing's father dies of (as one review put it) "a terminal case of coughing up blood".
Considering the amount everyone smokes in the series, this must be lung cancer.
In Kare Kano's play "Steel Snow", the Inventor's Forrest-Gump-esque first love Rose reappears to give him a baby to take care of, coughs three times, and promptly dies.
In Kodomo No Jikan, Rin Kokonoe's mother Aki coughs after being in perfect health for the rest of the manga. She's dead within a dozen pages. Fixed in the anime - she actually finds out that she has lung cancer, but decides the money for expensive treatment to prolongue her life for a short while would be better used to raise Rin as well as possible. She hides it as long as possible; by the time it becomes inescapably noticeable, it's too far gone, and Aki dies a relatively quick wasting death.
In the Black Butler manga during the circus arc Ciel is dragged off to the makeshift outdoor baths by his roommate. During this time it's winter and the water the circus performers are washing up with isn't heated (it's Victorian London, after all). After being soaked with the freezing water we later see Ciel coughing, eventually falling into an aggressive coughing fit that causes him to vomit. We find out that he suffers from asthma, a disease he inherited from his mother. The cold had aggravated it. He gets better, though.
Yuna Miyama from Maburaho starts coughing, but this is later subverted when Kazuki Shikimori dies healing her.
In Macross Frontier, the Incurable Cough Of Death is simply one of the V-Type Infection's syndromes (among dizzy spells, fever, keeling over at the drop of a hat...) that Sheryl Nome has to endure, even though Grace has claimed the V-Infection to be incurable and fatal. Her struggling to overcome these in order to reassert herself and her ideals seems to be one of the major plot arcs as the series nears its end.
However, Sheryl doesn't die, but is saved when Ranka uses her own Vajra skills to move the virus from her brain to her stomach region, turning it into more of a benign symbiosis than infection.
Parodied in Macross 7 Encore, where Millia comes down with a cough and assumes that she is dying. She begins doing a whole bunch of really silly things that she wants to do before she finally gives out. At the end of the episode, Dr. Chiba finally states his diagnosis: a cold. The cough was never anything more than a cough, but Millia overreacted due to apparently never having gotten sick before.
Precia Testarossa as well. Why is she coughing up blood? Who knows! Probably stress and overworking herself, even though we never actually see her doing much apart from whipping Fate.
It's possible that it's a sickness brought on by that magical reactor explosion that claimed her daughter's life, akin to radiation poisoning.
The movie manga reveals that she actually suffered from cancer.
In the anime Magic Knight Rayearth (second season), Anti-Villain Eagle Vision is in an advanced stage of this. He forces his friend and minion Geo to not reveal it so he can die a "warrior's death".
A character appearing on two episodes of the mecha anime Metal Armor Dragonar is shown to have this disease. However, he ends up surviving just long enough to see his two longtime compatriots killed, one by "friendly" fire, and then gets shot down himself after proving to be a significant enough opponent to elicit an upgrade of all three main Humongous Mecha.
Averted in My Neighbor Totoro, where Satsuki and Mei's mother clearly is in a clinic for tuberculosis but gets cured and sent home (after a few scares) in the end.
Justified in Nabari No Ou, as Yoite's entire body is failing as a result of his use of the forbidden Kira technique. It's explicitly mentioned later on that he won't survive the month.
Hiruluk of One Piece has a disease similar to this, in which he periodically coughs up blood. But this isn't what kills him; even when fatally poisoned by Chopper's misguided attempt to cure him, and facing death at the hands of Wapol's firing squad, he drinks a potion and explodes.
Doc Q and Stronger of the Blackbeard Pirates are also frequently shown coughing up blood; they have yet to die.
Sayo Muto aka Magdaria from Rurouni Kenshin's filler arcs is dying of tuberculosis. Specifically, she got it from her mother when she was a little girl, and her older brother Shougo tried to search for a cure to no avail. Neither mother nor daughter die of illness; both of them were shot to death, with several years of difference.
One could argue that it's played straight, in that the cough signals the audience that the character is doomed. Of course, the way the writers were practically splashing "Wouldn't it be so tragic if this character died?" all over the screen every time poor Magdaria appeared, most of us already knew that.
Kenshin, and then Kaoru contract some kind of unspecified disease in the Seisouhen OVA whose symptoms include this. (The fans called it "Super Tuberculosis".)
We know that since Rose of Versailles is a tragic shojo anime, that there's little chance that Lady Oscar will make it to the end of the series alive, but when she starts coughing up blood, that pretty much cinches it. Although, unusually, she doesn't actually die from the cough (though she is informed that it's terminal) but in a far more suitably dramatic manner while storming the Bastille and being shot to death.
Also, both the Dauphin Louis Joseph and Marie Antoinette had tubercolosis (a particularly painful osseous tuberculosis for Louis Joseph), althrough only the Dauphin died of it.
In one episode of Rune Soldier, Louie helps a little girl to find a rare flower for her grandmother, who has an unspecified sickness, that mostly consists of a bad cough.
In the "Dream" arc of the Sailor Moon manga, Mamoru hides his Incurable Cough Of Death from Usagi at first, but he is soon discovered. He also coughs up some black blood and, more significantly, has a black rose in his lungs showing this to be some sort of magic disease (apparently without followup testing for known diseases that can produce anomalous chest x-rays). It turns out it is a result of his kingdom, Elysion/The Golden Kingdom, that he ruled being attacked which affects him physically... once the enemy is defeated he is cured.
Raquel Applegate of Wild ARMs 4, due to suffering from an unknown, incurable disease that's implied to be radiation poisoning. This doesn't stop her from being the most powerful character in the game, though it does explain why her HP and speed are so low. She eventually dies in the Distant Finale epilogue, having never found a cure for her sickness.
Subverted in Wild ARMs 5, by the same character, but in a cameoappearance. Although she still has the cough, the player can go on an obnoxiously long Irrelevant Sidequest to cure her and give her a happier ending. Ironically, the thing you use is the same cure-all that had no effect on her in Wild ARMs 4.
Xxx HO Li C main character Watanuki- who is also the Butt Monkey / The Woobie of the show- suffers from the dreaded blood-coughing after befriending a lonely ghost whose presence sadly sucks out his life energy even if she doesn't want him harm in a episode arc. He does survive because another character kills the ghost with a spiritual arrow in order to save him, but it is made clear that it would have killed him if the situation would have continued any longer.
In the manga Emerging, a heavy cough that sometimes produces blood is one of the first signs that a character may have contracted the extremely deadly mystery illness that is spreading across Tokyo.
Takiko Ohkuda from Fushigi Yuugi Genbu Kaiden continuously coughs during her journey. When she's back in the Real World, it's revealed that she caught the consumption of her late mother, Yoshie. Then again, it's already revealed by Miaka that she originally was mercy killed at the hands of her father.
Aslan Battour from Kaze to Ki no Uta suffers from tuberculosis in the backstory. He's already dead in the main storyline.
In the Marvel 1602 miniseries, Queen Elizabeth I is shown coughing blood into a handkerchief. To be fair, she WAS rather old, and history records that she died in 1603. Count Otto von Doom's poison device renders the question moot, though.
In Green Lantern's Sinestro Corps War, Guy Gardner coughs in mid-battle, indicating that he's infected by the sentient bio-virus Despotellis. He soldiers on and fights, until eventually collapsing, before the Corps medic injects him with Leezle Pon, a sentient smallpox virus... who's also a Green Lantern. Two viruses enter, one leaves victorious.
Strangely averted in 52, when it is revealed that Vic Sage knew he was dying of lung cancer since before the start of the series, but the only hint of that is him disapproving of his protégées smoking, and that is treated like a Running Gag more than anything. Of course, once the cat is out of the bag, his symptoms starts to show. Fast.
In an issue of Teenage Mutant Ninja Turtles Adventures, the turtles find themselves in the Caribbean in 1492 in time for Christopher Columbus' "discovery" (It Makes Sense in Context), and one of the natives develops a cough, foreshadowing the epidemic from diseases the Europeans brought over that they themselves had immunities against.
In Hellblazer, this was how John's terminal lung cancer manifested itself, although intermittently enough at first that he spent a long time in denial.
In The Metabarons, Othon von Salza takes terminal damage to his lungs when he destroys the Shabda-Oud cetacyborg. He coughs up blood for the rest of the issue until he dies.
Played with in Marvel Zombies 4. Jack Russell/Werewolf by Night wanders off coughing. It's an indicator that Morbius' vaccine has backfired: when Jack is reunited with his team mates a little later he's turned into a zombie.
In the little known WHOO!Kingdom Hearts RPG! The character Reeves seems to have contracted one. Trolololo
Lady Silvermane in Whispers is stated to be old and sickly, and has a nasty cough that worsens with stress. She also keeps a handkerchief on her reading desk, which is mentioned to be drenched in blood, suggesting tuberculosis or some other lung disease.
In Alien vs. Predator, Charles Bishop Weyland not only has a cough, but actually listens to a story about someone who died because they were in no physical shape to take on the challenges that they faced. It doesn't take a rocket scientist to figure out that he won't be walking off into the sunset at the end of this movie.
Interestingly, he tries to hold off a Predator while the others escape, only for the Pred to scan him, see his mangled lungs, and walk past. Weyland is annoyed at being ignored and sets the creature on fire with his inhaler. Now the Predator is pissed and stabs the old man.
In Clear and Present Danger, Admiral Greer's mild coughing fit during a Joint Chiefs of Staff meeting heralds a diagnosis of pancreatic cancer, and he's dead two scenes later. To be fair though, pancreatic cancer does have an incredibly low survival rate.
Not to mention, pancreatic cancer is rapidly metastatic (it spreads incredibly fast), and by the time the symptoms appear, it's propagated too much to be effectively treated.
Another Western movie example: In the spirit of all the "beautiful young woman dying from tuberculosis" operas mentioned below, Nicole Kidman's character Satine in Moulin Rouge! is also dying from tuberculosis. In a slight subversion, she doesn't know she's dying (even though it should be pretty frickin' obvious), because Harold (her boss and father figure) tells the doctor not to tell her so she can continue to perform.
And because the doctor has told him there is nothing anyone can do, and Harold cares about her and does not want her to learn such depressing news.
Justified, as uncontrollable coughing up of blood is the strongest symptom of tuberculosis.
Subverted in Escape from L.A.: Up until the end of the film, everyone was convinced that Snake's cough was due to him being infected with a deadly toxin. Then, it was revealed that he and the audience had been duped; the "Plutoxin 7" virus he was given was actually a common influenza virus.
In The Host, coming into contact with the tadpole monster reportedly infects the touched with a lethal virus. When main character Gang-Du is infected, the media makes a big case about how he is exhibiting "cold-like symptoms", including coughing (which leads to some mild hysteria on the streets of Seoul when a man coughs in a crowd while the media piece is playing). Subverted in that the virus doesn't actually exist (the US Army stuck with the story because it was too late to say they were wrong), and Gang-Du probably just has a cold.
The mysterious virus in the film Right at Your Door seems to give people coughs and prompt tearful evaluations of life and the government.
At about the halfway point of the Andy KaufmanBio PicMan on the Moon, Andy coughs while explaining his latest stunt to his agent; later, during a comedy club appearance where he invites audience members to touch a cyst on his neck, he has a brief fit of coughing. These are both given no heed and the latter could be seen as All Part of the Show...but in the next scene Andy breaks the news to his confidantes that he has a rare form of lung cancer, which he eventually dies from. Notable because this is actually Truth in Television: Andy developed a cough in the mid-1970s, and he sometimes can be seen coughing in interviews. In 1983, when it became too frequent and pronounced to ignore, he took his loved ones' advice, went to a doctor, and learned that he was dying; the cough was a side effect of his illness.
Ratso Rizzo's persistent pneumonia gives him a cough of death in Midnight Cowboy.
In an essay about seeing this movie with his boyfriend, David Sedaris pokes fun at how this trope was used; "It might have been different had Julianne Moore suddenly started bleeding from the eyes, but coughing, in and of itself, is fairly pedestrian".
In Brians Song, the first big sign that something more than a little weight loss is happening is Brian Piccolo hacking and wheezing on the sidline complaining of hay fever and allergies. A fairly realistic example of this trope since he's actually got a tumor in his lung.
Justified in Brassed Off. Coal lung (caused by inhaling small particles of coal dust, which proceed to abrade membranes in the lungs) has all the symptoms, and is incurable and invariably fatal. Danny is a retired miner who has probably worked for over thirty years, most of that before protective gear.
Sarcastically parodied (of course) in Superhero Movie. The soon-to-be-villain has a brief coughing fit; the handkerchief he uses comes away with a blood splotch on it. When the protagonist asks if he's okay, the villain replies, "Oh, yes, I'm fine. This is healthy cough blood."
Longshanks, in Braveheart. Introduced subtly as a very mild sneeze; by the end he's dead from consumption.
Although considering the movie takes place over a number of years, it's excusable.
Finding Neverland, Sylvia Llewelyn Davies (Kate Winslet) is a widow with five young sons, so you think she'd want to look after her health for their sakes. There were consumption treatments and sanitariums (though no cure, some people DID recover) in Edwardian England, especially for a woman with money. But instead she says "I need to go on pretending...until the end...". That's about as useful as "think happy thoughts and you can FLY!"
The real-life Sylvia Llewelyn Davies had a better excuse for not seeking treatment: inoperable chest cancer. How that translates to a cough of doom is anyone's guess.
Subverted in the more historically accurate 1978 miniseries The Lost Boys: J.M. Barrie himself, a chronic smoker, is highly prone to coughing fits from the beginning, but it never manifests itself as a disease of any import.
Subverted by another real-life character played by Kate Winslet, Juliet Hulme, in Heavenly Creatures. Juliet suffered from TB as a child, and her relapse as a teenager is signaled by one scene of her in school coughing slightly and then spurting a tasteful amount of blood on her text book. She spends months in hospital, and helps her best friend Pauline murder Pauline's mother, after Juliet recovers.
Miss Potter - Ewan McGregor's character, Norman Warne. Mr. Warne's sister has to tell his fiancee Beatrix that Norman died suddenly, possibly caused by getting rained on at the train station to say goodbye to Beatrix. "It was just a cough!", Millie Warne says. Actually Norman Warne died of Leukemia, which apparently doesn't cause coughing, but maybe that's not nearly as "romantic"?
In Constantine, the titular Anti-Hero is dying of lung cancer, complete with bloody cough, and he knows it. In the end, of course, he tricks the Devil into curing him so he won't go to Heaven.
That wasn't a trick, that was the Devil being an asshole because he didn't want to lose; Constantine really shouldn't have given him the finger while going into the light...
In the novelization, it wasn't Constantine's fault he flipped off the devil. God made him do it as He carried Constantine into the Light.
Gran Torino - Clint Eastwood's character exhibits the cough complete with bright red blood and the coughing fits being violently enough to bring him to his knees. He passes it off as nothing, but a later scene with the doctor implies that it's a great deal more serious. He doesn't die of it, instead dying in a hail of bullets to make sure a violent street gang stays put away. Given the frequent smoking in the film and his advanced age, it's probably lung cancer.
Repo! The Genetic Opera has Rotti Largo, whose very first scene has him being brought the news that he's dying, and has very little time left. His only symptom is a rather bad cough, and of course, he's dead by the movie's end.
In fairness, they do hint that it's some kind of cancer—he's bald and has lesions on his face, which can both be caused by chemotherapy and similar treatments. It's the stress of the Genetic Opera that kills him by the end.
However, the cough had nothing to do with why he died. Obi-Wan shooting out his gutsack with a blaster took care of that.
The cough was actually from when he abducted Palpatine in the last episode of the first Clone Wars series. One of the Jedi knights force-crushed his rib-cage as he made his escape.
His rib-cage gets crushed TWICE, once in the Clone Wars comics (by Mace Windu), and AGAIN in the aforementioned miniseries.
Used in Shadrach where Paul's mother has a persistent cough, probably from tuberculosis, and dies a few years after the events in the movie.
In the Errol Flynn swashbuckler Captain Blood, Hanging JudgeLord Jeffreys coughs into a cambric handkerchief and is diagnosed by the eponymous hero as dying from "a bleeding death in the lungs." (In the novel and in Real Life, Jeffreys' fatal illness was actually kidney disease. (Admittedly, kidney disease is rather more of a challenge to show tastefully on screen...)
In Mildred Pierce the younger daughter gets the fatal cough after the first 15 minutes.
Strangely enough, Ram in TRON starts coughing after being mortally wounded.
In Iron Jawed Angels, Inez starts with a cough...then coughs blood...then dies. Same as her real life counterpart, she has pernicious anemia.
In the film adaptation of The Last Song, the main character's father has an ominous coughing fit shortly before his daughter(and the audience) find out he has terminal cancer.
In Inception, Saito (who had been shot in the chest in the first dream level) appears to be fine... until he starts coughing. By the time they've finished the third dream level, he's died and gotten stuck in limbo.
The James Eckhart indie film To Be Friends has one scene like this on a beach to establish that the lead female character is terminally ill, explaining why she and her best friend are in the countryside so she can commit suicide.
In Tangled, Flynn coughs just before his death from stabbing; perhaps blood got into his lung.
In Thérèse, Thérèse (soon to be St. Thérèse of Lisieux) develops a violent cough, complete with Blood from the Mouth, which proves to be tuberculosis.
Averted in Balto. The entire point of the story is that the titular dog-wolf hybrid had to help a dogsled team get medicine so that the diphtheria epidemic didn't kill most of the town's children. They are shown occasionally, growing weaker and often coughing weakly to get the point across, but Balto and the team make it in time to save them.
However, consider that one of the symptoms of Diptheria actually is a Cough of death - this is a bit of showing their work. Especially since in real life, the dog-teams did make it in time.
Also averted in The Secret of NIMH. Timmy is bedridden and coughing because he has pneumonia, but we're led to believe by the end of the movie that he's getting better thanks to the medicine his mother gave him.
The Van Dorts' servant Mayhew in Corpse Bride has a nasty cough at the beginning of the film that the Van Dorts complain about. He later succumbs to whatever was causing it and falls over dead while driving them home. They don't even notice aside from the sudden lurching of the carriage. He then shows up in the Land of the Dead as a "new arrival".
Byzantium: Clara gains this in her adult life before she turned vampire. She's also shown coughing up blood.
Lord Gyles Rosby, a minor character from A Song of Ice and Fire, was known for his constant coughing. Queen Cersei appointed him to her Council (because the alternative was Garth The Gross, a man troubled by constant flatulence) after which he promptly died.
Cersei: "Lord Gyles has had that cough for years, and it never killed him before. He coughed through half of Robert's reign and all of Joffrey's." ... "You will return to Lord Gyles and inform him that he does not have my leave to die."
In Charlotte Brontë's Jane Eyre, the minor character Helen Burns expires from consumption during a typhus epidemic. Helen's illness is portrayed quire realistically, though. Her general weakness is emphasised far more than the coughing, and she is well enough to more or less function for a long time. Helen, in both character and condition, was based on one of the older Bronte siblings (who died before getting famous), so Charlotte knew what she was talking about.
In "The Golden Road" by L. M. Montgomery, Cecily (after having always been more delicate than her friends, and spending a night with them in a bitter snowstorm) develops a persistent mild cough around the middle of the novel. She was otherwise perfectly happy and healthy for the rest of the novel, but after that point, the author begins to sprinkle in very subtle hints that she died soon after the book ended.
Such as adults commenting that she looks like a relative who died young, and a character predicting the futures of all her other playmates but limiting Cecily to that she will always be loved.
She did something similar with Gilbert Blythe in her famous "Anne" series. Though it wasn't a cough, other characters begin to notice that Gilbert is looking pale and thin around the middle of "Anne of the Island". By summer, it is revealed he has come down with typhoid fever. This turns out to be a crucial plot point; Gilbert being ill prompts the titular Anne to re-examine her feelings towards him, and she realizes she's in love with him after all. Unlike other characters (dead seems to be a common theme in her novels, both humorous and sad examples), Gilbert does not die.
Ruby Gillis, Anne's childhood friend, does die of "galloping consumption" in the same novel, but there is no issue of this being hinted with a cough, as Anne does not learn of Ruby's illness until just before the latter's death.
Averted and parodied in the Fourth Wall-abusing novel The Cat Who Killed Lilian Jackson Braun'. In one scene near the beginning Philip Roth—yes, that Philip Roth—coughs, and remarks that means he'll be dead by the end of the novel. The protagonist tells him that it's a parody and he shouldn't worry. As you've probably guessed, it's played straight in the end. Roth knew he was dying all along, and furthermore, had killed Lilian Jackson Braun himself, out of a deep-seated hatred of her books.
In A Dream of Red Mansions, Lin Tai-yu has one from her introduction. It escalates considerably after she makes a certain discovery.
Fantine in Les Misérables, of an unnamed illness probably tuberculosis. Apparently she coughs after every word - which doesn't stop her from delivering lengthy speeches on how happy she will be to see her daughter again. In the book, it both plays straight and inverts The Power of Love - she might be cured if her daughter is brought to her, but she dies of shock when these hopes are dashed by Javert. (Also, see Theater.)
Cryptonomicon has Lawrence's mom dying of what the book suggests was 1918's H1N1 flu. Incredibly justified - the 1918 flu was notorious for young, healthy people becoming sick one day and not waking up the next.
In The Kite Runner, the first sign of the illness that will kill Amir's father is a cough. Doesn't quite fit this trope because the novel goes into a lot of detail about his diagnosis of lung cancer. But later, in a textbook example, Amir (and the reader) are alerted to Amir's old friend Rahim Khan's fatal illness by his coughing up blood.
Invoked and Discussed Trope: in Henri Guigonnat's Daemon in Lithuania, here's Max-Ulrich describing his sister Kinga:
She sighed a great deal, she used to sink down on to the divans, and sometimes even faint. She would interrupt her wearisome embroidery, raising her eyes to the heavens (she was subject to strange mystical states), or let the heavy anglo-saxon novels, which she never finished, drop on to her knees. She often held a delicate batiste handkerchief to her lips, and coughed faintly. In those moments she paraded an ostentatious discretion, and a truly unbearable resignation. I kept a pitiless watch on her, and I can positively state that she never coughed the slightest drop of blood. But she had cultivated the art of languishing gracefully, and no doubt her head had been turned by romantic examples of phthisis, of homecomings from balls where you catch cold in the snow.
In the story Laura and the Silver Wolf, the heroine who has leukemia begins to cough... and from then on, she wakes up exactly once and then dies. But if we believe her, then she is forever in the Ice-Land and quite happy there.
Raistlin Majere in the Dragon Lance novels suffers from this over the course of his entire life to the point of more than once nearly blacking out/suffocating altogether because of particularly nasty incidents of it. Subverted because it doesn't actually kill him. Much of the description of the ailment points more toward it being asthma rather than anything outright lethal despite many occurrences of Blood from the Mouth.
In The Tartar Steppe by Dino Buzzati, in the first scene where Lieutenant Pietro Angustina appears, this is how readers are clued in that he's elegant, self-possessed, and ill: "Angustina had a slight fit of coughing. It seemed strange that a sound so disagreeable should proceed from such a refined young man. But he coughed with due restraint, lowering his head each time as if to indicate that he could not help it — that it was really something he had nothing to do with but which he must endure. So he transformed the cough into a kind of willful habit for others to imitate." Seventy pages later, Angustina dies an elegant and self-possessed death.
Played literally and horrifically straight in Plague by Michael Grant. In the book several characters contract a cough that causes them to cough out their lungs out.
In Infernal Devices Jem's illness that causes him to cough up blood. No cure has been found.
That is until the epilogue where a cure was finally found.
I know when somebody usually coughs in a story it means they're gonna die, but the Chief had had that cough ever since I met him.
In Chime, catching the swamp cough means almost certain death, and several children die of it before the end of the book. Rose (the protagonist's twin sister) starts coughing midway through the book, leading Briony to fear for her life enough that she asks the Old One in the swamp if Rose is really sick. Turns out Rose didn't have swamp cough, just a normal cough...until the Old Onegivesit to her to force Briony to stop the draining of the swamp. She succeeds, and Rose (barely) survives. The swamp-draining plan was also the reason behind the unusually large number of swamp cough cases that year.
Episode "Awakened" of Charmed opens with Piper coughing up a storm and Phoebe trying to convince her to go home and rest. Piper insists she's fine. She collapses two minutes later. She's in a coma within a day. Her life is only saved via magic, conventional medicine is shown to be unable to save her.
House pretty much gives two giant middle fingers to this trope, because Dr. House's patients just about never die. Except that one time. "But... it's just a cough."
Played with in I, Claudius, where Gemellus's chronic cough is fatal because it really annoys Caligula.
This was also used with Londo as Foreshadowing. Londo, being a Centauri, has seen a vision of his own eventual death, but no context for the scene (seeing their own deaths in a vision is one of several hats the Centauri wear). One of the details of the scene is him having a sickly cough (though he knows from the beginning it's unrelated to his actual cause of death: being strangled to death by G'Kar). Starting from late in the second season, we see Londo cough occasionally, Word of God being that it is foreshadowing his eventual fate.
Played With in the Made-for-TV MovieThe River of Souls, when a Soul Hunter arrives on the station. It is mentioned that Soul Hunters always appear shortly before someone important dies... and Zack Allen coughs. Played for Laughs when he immediately begins protesting that he's not sick, is not dying, and only coughed because his throat itched.
On The 4400, people whose bodies don't accept promicin get one of these before death.
In an episode of Friends, Phoebe poses as Chandler's dying wife to help him get an engagement ring for Monica. She coughs rather casually to emphasize the point that the other man is going to "break a dying woman's heart", prompting Chandler to explain that she's dying "of a cough, apparently".
Parodied in another sketch, in which a terminally ill man gets his best friend to fulfill his increasingly extravagant dying wishes by putting on a sickly-sounding cough.
In an early episode of Scottish Sketch ShowChewin' the Fat, Ford Kiernan and Greg Hemphill are discussing movie tropes, one of which being that the minute you see a young child (no matter how healthy she may seem) cough, she's probably going to die.
Analyzed in a SNLsketch with Alec Baldwin, where he hawks DVD #72 in his instructional acting series: "First Coughs: Foreshadowing Your Character's Death." Actually provides a pretty good breakdown of the various ways it's commonly handled, including "Ignoring It," "It's Just a Cold," and "I Don't Need Any Damn Doctors." The Advanced lesson is "Coughing Into a Handkerchief, Seeing Blood in It, Looking Nervously Around, and Hiding it in Your Pocket".
The 2005 BBC adaptation of Bleak House by Charles Dickens; Richard Carstone works himself to death over the Jarndyce vs. Jarndyce case in hopes of getting his inheritance for himself and his pregnant wife, Ada... rather than staying alive by going to the doctor's and getting a regular night's sleep so he can provide for them. Plenty of "it's nothing!"s and "it's just a cold!" abound, and NO ONE forces him to get help until it's too late.
Actually, they DO try. Esther asks Woodcourt to keep an eye on him, and Ada is clearly worried - she tries to persuade Richard several times to give up the case. Apart from that, there's not much they can do, which is one reason why his decline is so painful to watch - everyone knows Richard is sick, but he is a) deeply in denial, and b) obsessed with the court case to the point that nothing else matters to him.
Jo also contracts some sort of illness (in the book it's smallpox) that causes him to cough blood. Unlike Richard, he does try to seek medical help, however a crooked lawyer tells a constable to force the boy to stay away from people. Ultimately he is found by most of the main cast and brought in for rest. Though he still dies, he at least is safe and relieved of feelings of guilt (worried that he caused Esther to die of the disease as well).
In Deadwood, Doc Cochrane begins hacking up blood in the third season, and Silas and others describe him as "a lunger," implied to be tuberculosis. Cochrane starts getting depressed, but Swearengen gives him a tough-love pep-talk, telling him that he isn't dead yet and to get back to work. Of course, the fact that Cochrane is the only doctor in town means Swearengen and the rest of the town residents rely on him. Subverted, since the Doc lives to the end of the series.
Don Fernando in the ridiculously Narmy educational Spanish-learning program Destinos has one of these. He has it throughout the entire 52-episode series and doesn't die. Supposedly, he dies of it after the end.
Subverted in Breaking Bad, where the protagonist has been diagnosed with lung cancer at the start of the show and becomes a drug dealer to make money fast for his family. In the episode where he starts coughing badly and even spitting up blood, he assumes he has little time left, kicking off a rather dark take on Like You Were Dying. It turns out it's just a reaction he's having to the medication, and the blood is from a slight tear due to all the coughing—he's actually in remission.
He: Well, what kind of fish you got that isn't jugged?
He: What, rabbit-fish??
She: Err, yes. It's got fins...
He: Is it dead?
She: Well, it was coughing up blood last night.
In one Sliders episode, they end up in a world where a disease ("The Q") is spreading throughout the world, and wiping out humanity because, as a paranoidly clean society, they never discovered penicillin. Anyone who coughs has the disease (and often try to cover it up).
Angel: Fred is killed when her body is taken over by an ancient god. The first symptom? Coughing up blood.
On LOST, Richard's wife dies shortly after coughing up blood. The soundtrack identifies her illness as pneumonia. This occurs in 1867 in an isolated town on the Canary Islands, so her prognosis is reasonable.
Played frighteningly straight with Kamen Rider Dragon Knight as Chris Ramirez, aka Kamen Rider Sting, had asthma severe enough to get him discharged from the Marines. It probably wasn't lethal on its own, but when given the offer to be a Kamen Rider he Jumped at the Call. After that he really aggravated his condition with all the superheroics, ignoring every warning sign along the way. At least when he went out, it was by Heroic Sacrifice instead of illness (and due to being a Fate Worse than Death that turned out to be not really, he was able to come back in the epilogue and the heroes now could use Phlebotinum to cure him).
While not Chris' counterpart, the series from which Dragon Knight adopted its footage, Kamen Rider Ryuki also contains one such character in Shuichi Kitaokao/Kamen Rider Zolda. In fact, its more or the less the main reason why he becomes involved in the Rider War as he wants to use the promised wish to grant himself immortality, thereby curing himself. By the end of the series, Shuichi decides to quit the Rider War deciding to enjoy what little time he has left. However, he also begins to feel the need to take some personal responsibility over his role in allowing his Arch-Enemy to become a Rider, and decides to fight him one last time. Before he gets the chance, however, he succumbs to his illness and dies. Even taking the Reset Button ending into account, there's no indication that things will turn out any better for Kitaoka, and worse, he'll probably never go through the Character Development he did in the series and grow out of his Jerkass tendencies.
In the NUMB3RS episode, "Janus List", the a bomber, Taylor Ashby coughed a few times in the beginning before being blown up by one of his bombs. Later, it was revealed that he was poisoned and that he only have a short time to live even if he wasn't burned.
Practically invoked and inverted in Scrubs episode "My Lucky Night". Dr. Cox's son Jack develops a cough, which turns out to merely be the sniffles, but that doesn't prevent his dad from charging down the hospital hall like a mad bull, violently shoving over other doctors and patients. Dr. Norris, Jack's pediatrician, explains to Cox that as a doctor, he has to deal with the burden of knowledge, knowing what can really go wrong, and that he has to take control of it or it will ruin him. In the episode's closing scene, Cox is lying in bed, panicking about Jack's coughing.
Subverted in Criminal Minds episode "North Mammon". Three teenaged girls were kidnapped by a man and held in a cold, damp cellar. Just before this happened, one of the girls had coughed, indicating that she was getting a cold. That same girl grew worse and worse in health due to her surroundings as she and her friends were locked up. In order to be let go, the kidnapper made the friends choose among themselves which one of them would die in order for the other two to be let go. One of the healthier girls made up her mind to kill the sick girl and was trying to convince the other healthier girl to help, but in the end the sick girl bashed the former's head in with a hammer in order to survive. She and her remaining friend made it out of the cellar alive, but horribly shaken up from the experience.
An non-lethal example from an episode of The Cosby Show. Cliff is rushing about preparing an anniversary dinner for Claire. About a third of the way into the episode, he begins to cough, and by the episode's end, is laid up in bed with the flu.
The Tudors features this at one point, where King Henry's sister starts coughing up blood and dies within an episode. Henry mildly lampshades the suddenness by telling her husband (who is his best friend) in an accusatory tone that "You didn't even tell me she was sick." Unfortunately, somewhat Truth in Television... the real life woman died of tuberculosis, which was quite common at the time and manifested primarily as coughing and later hemorrhaging from the lungs.
Captain Keene is a very old and frail man who coughs and wheezes all the time. It's clear that he's dying. He dies after the obligatory two thirds of the episode, but interestingly enough, he died when his ship Justinian was attacked and sunk by the French.
Finch, a lower-deck character, feels dizzy and feverish, and falls down from a mast. He coughs while his fellow sailors try to nurse him back to health, and even Mr Hornblower is invested in his recovery. It doesn't help that they are on half-rations and his fever doesn't disappear. He dies very soon.
JAG: This is a symptom shown by the submarine crew exposed to an unshielded nuclear weapon in "Enemy Below".
The Walking Dead:A boy named Patrick develops this in the season 4 premiere, and by the end of the episode he's dead and re-animated. This results in a walker outbreak inside the prison, necessitating a massive quarantine.
Doctor Who: In early serial "The Sensorites", Ian develops a case of this. He goes from coughing to unconcious and dying in about two minutes. Fortunately, he has a natual immunity — he's a program regular.
Cases of the 1st Department: Mjr. Plisek is a heavy smoker and he coughs from episode one. In "48 Hours", he has a coughing fit and spits blood. All points to lung cancer, but it's something less serious and he's cured after an operation. Subverted.
Older Than Radio: The "coughing tragic consumptive heroine" trope dates back to the 1852 novel and play La Dame aux Camélias by Alexandre Dumasfils, as well as the opera La Traviata and Greta Garbo film Camille based on it.
Mimì from Puccini's La Bohème is another operatic character who coughs and faints her way to a tear-jerking death scene. Mimi from Rent fares much better.
Both of the above were based on real people (though Mimi very loosely so). What makes La Boheme even more depressing is that the real 'Rodolfo' also died of TB shortly after writing Episodes from the Artistic Life, as did most of the main cast. (Except Musetta... who saved up money to quit prostitution for good after 'Marcello' died, and sailed away to start a new life in French Tunisia... only to be killed when her ship sank.)
In Long Days Journey Into Night, Edmund coughs frequently; he subsequently learns he has tuberculosis. He tries to hide the truth from Mary, his morphine-addicted mother, by passing it off as a "summer cold." In the heart-rending final scene, as the relapsing Mary thinks she's back in her adolescence, Edmund tries to break through to her by shouting, "Mother! It's not a summer cold! I've got consumption!", but she's too far gone for this to register.
Double Subversion in Martin McDonagh's play The Cripple of Inishmaan: Cripple Billy, having a pronounced cough from the start of the play, produces a doctor's letter diagnosing him with TB, and is seen to die of it in a Hollywood motel room. It turns out that he forged the letter so that Babbybobby, the boatman whose wife died of TB, would take him to Inishmore so that he could be in the film Man of Aran. His "death scene" is actually him rehearsing his lines in his motel room. And then after Billy returns to Inishmaan when, irony of ironies, it turns out that he has contracted TB after all, complete with Blood from the Mouth. On a related note, the play is also a Deconstruction of Bury Your Disabled.
Fantine in the musical Les Misérables, of tuberculosis. However, it's difficult to convincingly fake tuberculosis and sing heartbreaking arias at the same time, so it depends on the actress sneaking in a few coughs when she has the time. (The French concept album was more explicit, where Fantine actually sings, "Inspector, I'm sick, sometimes I cough up blood.")
In Mega Man X, Dr. Light has this both during the flash back at X's ending sequence in the Continuity Reboot of the first game called "Megaman: Maverick Hunter X" and in the Megaman X: Day of Sigma OVA included in the said game during the flash back showing Dr. Light creating X on his final days.
Though, considering the amount he smokes...and he's had his cigs from the first game, and possibly even through training...
He doesn't really cough until he's horribly burned in a fire at the end of Act 3. Prior to that, he's actually mostly okay. Likely he inhaled the superheated air and burned his throat.
At the beginning of Hector's path in Fire Emblem 7, Uther of Ostia coughs during a conversation with Oswin. This pretty much seals his fate.
In Uther's case, it doesn't really help that he's apparently putting an insane amount of stress on himself and barely sleeps; he may have lasted a little longer if not for that. Also of note is the fact that his and Hector's parents apparently died of the exact same illness.
Ukyo from Samurai Shodown has long had such a cough, but is a subversion, as his popularity makes him essentially immune to the death he was set up for.
Ukyo's Seppuku takes advantage of his tuberculosis - instead of killing himself somehow like the other characters, his disease finally kills him.
At the end of the introduction of Dragon Quest V, the lead character's mother manifests one of these as an explanation of why she isn't present when the game proper kicks off. It's actually a trick, though — she's still alive, and gone for entirely different reasons.
In Dragon Quest IX, the wife of the resident archaeologist in one of the earlier towns in the game has a cough, attributing it to allergies and dust. She ends up dying of the contagion/curse that was killing off the townspeople just moments before the heroes manage to stop it.
In Silent Hill 2, at the end of the Maria ending, Maria coughs, and it is implied that what happened with Mary will happen again with Maria.
Subverted in Prince of Persia: The Sands of Time. In the first few cutscenes, the Vizier is shown coughing violently, getting blood in his handkerchief. Since he wasn't in a fight beforehand and this has nothing to do with his later death - either of them - it may actually fall under Vader Breath.
The relevance is more character-driven than plot. The cough and blood show that the Vizier is dying of Tuberculosis. It is this impending mortality which drives him to seek the Sands of Time (and the immortality they can provide).
Shinjiro in Persona 3 coughs on occasion, the only real sign the meds he takes to keep his Persona under control have wrecked his health. Interestingly, this is worked into gameplay: during combat, when someone misses with a melee attack, there's a chance they'll trip and be left prone for a round. Shinjiro doesn't trip - he bursts into such a severe fit of coughing that he drops to his knees.
And then we have the Ill Boy Akinari Kamiki, the Sun Social Link, a frail, thin young man who has this nasty tendency to go into such fits of coughing that he ends up briefly unable to speak. The name the game gives his Social Link says it all: "Dying Young Man". Notable for actually giving an identity to his ailment (a terminal genetic disorder). He actually does fall victim to his illness, and it's hinted that it's his ghost who gives you his book as aTragic Keepsake if you max said Link. Also, his soul will cheer on you before you go fight the Big Bad.
Mass Effect 2: The quarantine in Omega is in place because of a disease that starts off as a simple cough.
"It starts out as a cough, then you start coughing blood. And then... well. Then I shoot you."
If he survived Mass Effect 2, Thane Krios is coughing when met in Mass Effect 3. In this case his terminal illness was already known. He'll later be seriously wounded and die due to complications resulting from his illness, keeping with the trope.
When "Archangel" was active on Omega "cleaning house", there was a serial killer who also was a biologist specialized in virology. His cause of death was found to be "a cough". Since the killer was a Quarian, "Archangel" simply coughed on him to kill him.
In inFAMOUS 2 The hero's buddy, Zeke develops a cough soon after the plague becomes a part of the plot.
In Unreal, you'll sometimes hear Nali cough for no plot-relevant reason.
The Joker in Batman: Arkham City has a cough that gets more pronounced as the game goes on, thanks to his TITAN poisoning from the last game. This is also one of the few cases where Joker Immunity gets thrown out the window.
Zhuge Liang in Dynasty Warriors 6. Oddly, he actually survives, unlike the real person.
Guo Huai in Dynasty Warriors 7 has this as his primary character trait. He still manages to kick all kinds of ass with his ancient Chinese machine gun, despite keeling over after performing most of his special attacks.
Subverted in Trauma Team when Naomi Kimishima coughs up blood near the end of the game, a symptom of the fatal Rosalia virus. It turns out to be the virus, but she's saved from it by CR-S01.
Terry Fawles from Ace Attorney falls victim to this in 3-4 from ingesting poison.
Cave Johnson in Portal 2Cave Johnson acquires a fatal illness from handling moon rocks, and his intercom messages are frequently interrupted by violent coughing fits. Somewhat justified since it's speculated that lunar dust could cause respiratory disease.
A character in Illusion of Gaia coughs when you first meet him. He turns out to be your opponent in a Russian Roulette-type game, which he was playing to earn money for his family, since he knew he was dying anyway.
During the opening sequence of The 7th Guest, we see a girl dying of a "mysterious virus" and hear her coughing rather persistently.
In The Sims Livin' Large, there's the so-called Guinea Pig Disease that your sim can catch if (s)he doesn't keep his/her guinea pig cage clean. Once the guinea pig has bitten the sim, (s)he will start coughing and sneezing and will most likely die in the next few days if (s)he's not treated. The "incurable" part of the trope is subverted, though, because it can be cured in two ways: either buy the Forgotten Guinea Pig painting and wait for several in-game hours or let one of your sims use the Concoction Station several times until (s)he gets a white potion, then let the ill sim drink it.
In Disgaea 3, Almaz starts getting sick when he's pricked by needle thus suffering an incurable curse. He insists that he's fine the majority of chapter 6 and 7 until finally he drops dead due to progressively getting weaker. Only in the bad ending does he stay dead. Other than that, he'll get better.
Pokémon Conquest surprisingly has this with Hanbei. Once you beat his episode, he starts coughing up a storm. When Hideyoshi asks if anything is wrong, Hanbei just responds that he got too excited. Kanbei doesn't believe a single thing he said though which causes Hanbei to glare at him saying not to say anything before switching the subject on something funnier. Naturally Hanbei didn't die on screen, but given his real life counter part died of tuberculosis, it's easy to assume that he died shortly after.
Brothers A Tale Of Two Sons begins with the father having contracted what Ben Croshaw described as "the old classic unspecific-persistent-cough disease", and the two protagonists are tasked with finding a cure before he dies of it.
Hakuōki follows The Shinsengumi from before the Ikedaya Incident up to the end of the group, and thus unsurprisingly shows the onset of Okita Souji's tuberculosis and his struggle to cope with his illness. In most routes, it takes him out of the story entirely right around the onset of the Boshin War just like his real-life counterpart; in his own route (and in the anime adaptation) he manages to stick around a little longer thanks to becoming a fury, but his cough doesn't entirely go away and even his ending implies that he's living on borrowed time.
Barely averted with Tear in Tales of the Abyss. The cough, like several examples on this page, comes from poison, which in every other case (meaning the NPCs) plays this trope straight when they come on contact with the miasma. The first case is only averted because a dying Ion takes Tear's poisoned fonons out of her body when his fonons dissipate. Tear does play the trope straight when it comes to fainting, trying to cover it up, and pretending to be getting better. Overlaps with Definitely Just a Cold sometimes.
Her not dying is also Justified because unlike the NC Ps, she was born and raised in an environment that had miasma so had a higher tolerance to it that than the NC Ps, who experienced sudden exposure of a lot at once.
Keychain of Creation: Secret, shortly pre-Abyssalization exhibited this in a flashback, complete with blood, after catching a plague of some sort.
Cheap Thrills: Jeordie has been coughing up a storm for the last couple of chapters, worrying both his dad and his girlfriend. He tells them both he's fine. He's not - though we don't quite know what's wrong, yet.
Elizabeth Avery's cancer manifests itself this way in lonelygirl15.
In Marble Hornets, the more wrapped up in whatever happened to Alex Jay gets, the sicker he seems to grow. Entries set in the past show Tim having a similar coughing fit. The following seasons show this is the least of his health problems - without meds, he turns back into the Masked Man, which involves something approaching a seizure.
The "Slendycough" idea got picked up by a few other stories in The Slender Man Mythos, with one suggesting that it's due to Slender Man dragging the victim back and forth through time, which the human body is not designed to handle.
This trope is spoofed in the Animaniacs movie Wakko's Wish, in which Dot constantly coughs and claims she "needs an operation" but never mentions quite what the problem is. At the end of the movie, she does a Disney Death that lasts for less than five minutes (Those acting lessons paid off!), and is later shown emerging from the operating room with a new beauty mark to make her "even cuter".
Parodied in the South Park episode "Kenny Dies". Kenny randomly starts coughing during one scene, and if you can't guess where it leads to, take another look at the episode title.
Probably Muscular Dystrophy, judging from the vague descriptions we get.
Also spoofed in American Dad! "Tears of a Clooney". Hayley randomly coughs during one scene, which sure enough leads to her developing cancer (though she ultimately does not die.)
In an animated short called The Kinematograph. It's a truly heartbreaking story about a man attempting to create moving pictures (aka movies) in color. His wife is the one who tells him her theory on how to make color film, which ends up working. However, as soon as he leaves the room, she starts coughing. When he finally makes it work, he asks her to sit down in front of the camera and talk so he can film her. After he's developed the film and is excited to show her, he finds her collapsed on the floor near a bloody handkerchief. She dies, and all the man is left with is the film of her he was so eager to make.
In The Simpsons, Poor Violet is one half of a pair of orphans who always show up in Springfield whenever a heartstring needs tugging. She suffers from this. Most likely due to living in an orphanage that can't afford the proper number of walls.
Poor Violet: Three is not enough ... (COUGH HACK COUGH)
A bad nosebleed can cause blood to drip into the throat. Naturally, this causes coughing, and while obviously not fatal, it's unsettling and by no means fun. It can be even worse in the winter, when it's easier to be dehydrated and when it's easier to catch an illness, thanks to everyone staying indoors in close environments.
Legendary gunfighter Doc Holliday eventually died of tuberculosis. It's said that knowing he was terminal was what made him such a Death Seeker in the first place. (Reportedly his last words were "This is funny." He'd always thought he'd die with his boots on but found himself dying in bed looking at his socks.) Accounts of his Incurable Cough Of Death can be found in the historically inaccurate (but still pretty cool) movie Tombstone or here.
Averted, Post-nasal drip can cause continuous coughing but by itself wouldn't likely cause death. Have fun scaring people though.
A rather common symptom of bronchitis, which is not normally fatal, is rusty colored or blood streaked sputum. Which unfortunately is a common sign of pretty much every ER worthy lung disease.
It's also not entirely difficult to tear a blood vessel in your throat by coughing or vomiting and seeing blood, which doesn't have any serious consequences.
Prolonged periods of heartburn or other ailments that cause stomach acids to go into the throat, (GERD) can result in the vocal cords making large amounts of mucus to defend itself. This results in a nasty cough, that most likely will not harm you.
A common allergy can be met with advice to "go home before you infect anyone".
A non-human example: If your computer's hard drive does strange clicking sounds, you can almost certainly tell that it's doomed.
Pertussis aka Whooping Cough. It's usually only fatal to infants (which just makes it worse), but even in older kids it can cause fainting, hernias, and rib fracture. It's also very unpleasant to endure, being that the endless deep coughs can make a person feel like they're dying, even in mild to moderate cases.
French playwright and actor Molière, who suffered from tuberculosis, is famous for having collapsed into a coughing fit while performing in the last play he wrote, ironically titled The Hypochondriac (La Malade imaginaire). Despite coughing up blood, he insisted on finishing the performance. Afterward he had another fit of coughing and hemorrhaging before being taken home, where he died a few hours later.
Composer and Pianist, Fryderyk Chopin, was almost as famous for his consumption as he was for his music (he finally died of it at age 39).
As mentioned in the Rose of Versailles entry above, both queen Marie Antoinette and her second son Louis Joseph had tubercolosis, with Louis Joseph dying of it (and his illness having a deep impact in the relationship between the royals and the Estates-General due the latter refusal to allow the king and queen to visit their dying son), while Marie Antoinette was executed before it reached that point.
Cases of cystic fibrosis can cause this, due to the mucus the body produces becoming thicker and clogging the lungs and other parts of the respiratory system. Subverted by the fact that treatment for the disease is improving and life expectancy for the affected is much higher than a few decades ago.
General Lazare Hoche died of tuberculosis at 28 just a few days after he started coughing violently (and bloodily, according to some accounts). Since his death was very sudden and he was one of the most prominent French generals at that time, there was rumors that he had been, in fact, poisoned, but his autopsy did not support this.