-> Her condition was a case of ''terminal moe'', a dangerous illness which crops up in anime whenever they want to make a character more sympathetic through illness but don't want to actually attribute a real illness to them.
-->--''[[http://www.fanfiction.net/u/1263379/gabriel_blessing Gabriel Blessing]] comment on the real illness behind [[{{Sekirei}} Chiho]]'s condition''

Common ailment found on the SoapOpera. It is notoriously difficult to diagnose, and often exhibits vague symptoms. Often fatal, but victim can linger on for a long, long time. Sometimes results in a lengthy coma which, upon the victim's recovery, may also manifest a radical change in appearance (see: TheOtherDarrin).

Creator/JMichaelStraczynski has mentioned one riff on this, in which a soap opera writer supposedly put a character into a coma with very specific and carefully-researched symptoms, for a plot that was only supposed to last a couple of episodes... and then realized that if the character's recovery was delayed, he could continue to crank out script after script without ever needing to worry about a pink slip, since nobody else on the writing team knew enough about the disease to write the character's recovery. The actress didn't mind either, since she got a paycheck day after day for a few minutes' lying absolutely still in bed. The producers were somewhat less than pleased at this.[[note]]Rumor has it that a couple of years later, the same writer called the producers asking if they needed his services again; he was told that the producers were still in a coma.[[/note]]

The anime trope of the IllGirl suffers from the same plague of vague. See its page for the full story but the gist of it is the same; some kind of frailty to gain sympathy.

A common mutation anywhere is the IncurableCoughOfDeath; a terminal illness with no symptoms of any kind besides coughing. More likely than not evolved from VictorianNovelDisease. The character may insist the illness is DefinitelyJustACold. Not to be confused with SoapOperaRapidAgingSyndrome, which isn't actually a disease so much as a PlotHole that sucks up children and spits out teenagers.
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!!Examples:

[[foldercontrol]]

[[folder:Anime & Manga]]
* At one point in RanmaOneHalf, Master Happosai suffers from a case of this. Unfortunately, he gets better. Also, the teacher Hinako Ninomiya had a case when she was young. She gets better as well.
* Sahana from ''Sundome'', with her nosebleeds, dizzy spell and [[IncurableCoughOfDeath bloody coughs]]. [[spoiler: In the end, it gets her, and there is nothing that can be done. Hideo does his best to make her last days happy. He succeeds with that.]]
* In Ghibli's "The Borrower Arrietty", the male protagonist Sho has a heart condition ever since he was a child. Just a short period of physical activity can cause him pain.
* In VisualNovel/{{Clannad}}, Nagisa suffers from an undefined disease which prevents her from attending school from time to time. [[spoiler:Her daughter Ushio gets the same undefined condition. In both cases, it turns out to be fatal.]]
** [[spoiler:[[SubvertedTrope Or at least until the ]] ResetButton [[SubvertedTrope is used in the final episode/"true ending" of the game.]]]]
* MadScientist Ghinias Sakhalin in ''MobileSuitGundamThe08thMSTeam'' has some sort of disease that he has to take medication every day for. It mostly looks like paranoid schizophrenia, but he does have some poorly defined physical symptoms as well. The symptoms seem to fit Wilson's Disease, a genetic disorder that prevents the body from metabolizing copper properly whose most common symptoms are brain damage that often presents with schizophrenia-like symptoms and liver disease.
* Trisha from ''Manga/FullmetalAlchemist'' died of such a disease. It's never stated what it was but fans consider it either stress-related or cancer.
* Similarly Tsukimi's deceased mother in ''PrincessJellyfish'' had a vague, deteriorating disease that apparently lasted a few years. Eventually she was hospitalized and died.
* ''Franchise/KagerouProject'': Haruka Kokonose ([[spoiler:Konoha's former self]]) has a rather ambiguous illness (although a shot in the ''Konoha's State Of the World'' PV seems to imply it's a heart condition) that lands him in hospital for weeks, and prevents him from participating in physical activities. [[spoiler:He dies at 17, after a few-months-long {{Timeskip}} after his introduction. However, since it was triggered by the BigBad on purpose, we'll never know how long he would have lasted on his own]].
[[/folder]]

[[folder:Comic Books]]
* Miss Grundy gets diagnosed with this in the first issue of ''LifeWithArchieTheMarriedLife'', and dies a few issues later as a result.
[[/folder]]

[[folder:Film]]
* Dancer In the Dark, a drama and musical film, focuses on a female protagonist who has a genetic disease that causes her vision to weaken as she gets older. Early on in the film, she is already clinically blind, and this serves as a big element of the plot.
* Parodied in ''TheLivingWake'' where the self-deluded main character is certain he will die of "a vague and grave disease" despite clearly being in perfect health. [[spoiler:He ends the wake by stepping ceremoniously into a coffin where he instantly dies.]]
* ''LoveStory'' has been accused of playing this straight. (see Magazines, below.)
[[/folder]]

[[folder:Literature]]
* ''Literature/InfernalDevices'': [[spoiler: Jem's. It was caused by a demon drug that was used to torture him and his parents when he was younger. There is no known cure for it, and he has to keep taking a specific drug to keep on fighting - as Brother Enoch says, taking the drug means a slow death, but keeping him off the drug would mean a quick one.]]
* Appears as Drummant's gift in ''Literature/AnnalsOfTheWesternShore''. {{Justified}} because that seems to be the whole ''point'' of the Drum gift, which is called "wasting". The victim just gets weaker and weaker for no apparent reason until they eventually die, which takes about a year. [[spoiler:This is how Melle, Orrec's mother, dies.]]
[[/folder]]

[[folder:Live Action TV]]
* ''Series/BuffyTheVampireSlayer'': In the comics, it was retroactively explained that Drusilla was tortured by an "Inquisitor" while in Prague, including the use of a magic torture chair, leaving her in a frail condition. Spike initially hopes the Hellmouth will restore her, but later learns that the blood of her sire (Angel) can cure her affliction.
* Averted in non-American soaps, which are more concerned with realism. The closest thing seen on ''HomeAndAway'' is probably diabetes.
** Although Alzheimers' Disease, which normally takes years and years to build up, not only progressed ten times faster than real life, but then slew Mike Baldwin in a matter of mere ''months'' in ''CoronationStreet''
* Appears in, of all things, the profiler procedural ''CriminalMinds''. In an early episode, in a very dramatic scene, Hotch's son has had to go to the hospital to get "some tests" done and it turns out he has "a condition". This is [[BigLippedAlligatorMoment promptly never mentioned again]].
* The protagonist in OneLiterOfTears suffers from a harsher and much rarer kind of this.
* The first episode of ''MrShow'' opens with Ronnie Dobbs doing a PSA for his disease "Entitilitus." He notes that no one knows where it comes from or what it is but "entitilitus kills." Toward the end of the episode, when Terry sells the rights to make a {{Biopic}} of Ronnie [[spoiler:after he dies]], movie!Ronnie reveals to movie!Terry that he suffers from entitilitus [[spoiler: [[DiedInYourArmsTonight then dies in his arms]]]].
* This is essentially the fate of [[spoiler: The Mother]] in ''Series/HowIMetYourMother]]. The disease is fatal, and that's pretty much all we know about it.
[[/folder]]

[[folder:Magazines]]
* Magazine/{{MAD}} referred to this as "Old Movie Disease" in their parody of the movie ''LoveStory'', along with the claim that it makes you more attractive so you can die a beautiful death.
[[/folder]]

[[folder:Video Games]]
* In ''EternalSonata'', if you're able to use magic powers, it also means that you have vaguely defined illness that is eventually fatal, though it's hard to say exactly when.
* Any KeyVisualArts game will have at least one IllGirl that suffers from this, with the exception of ''VisualNovel/{{Planetarian}}'' where the disease is [[spoiler:low battery power with no way to recharge]].
[[/folder]]

[[folder:Web Original]]
* Inverted in the ''{{Paradise}}'' setting, in which humans are randomly, permanently Changed into {{Funny Animal}}s by causes unknown. The change is InvisibleToNormals, to whom the Changed will still appear to be his old human self. In order to prevent Changed from being injured by medical practitioners because of physiological differences the medics can't see, the Changed invented a fictitious ''real-world'' disease—-"Sleeping Sickness (Ivory Coast Variant)"-—and issued medical alert bracelets for it so that a Changed or Known physician could be alerted at need.
[[/folder]]

[[folder:Western Animation]]
* Mocked (as with many other soap opera tropes) in the ''[[SoapWithinAShow All My Circuits]]'' segments of ''WesternAnimation/{{Futurama}}''.
** "That was so terrible, I think you gave me cancer!"
[[/folder]]
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