In Real Life, when you go to a doctor and explain your symptoms, the first thing the doctor will do is test for the most common diseases that could cause them. Most of the time, this allows for a quick diagnosis, and the doctor can easily move on to the treatment. If the doctor discovers that the most common diseases are not the culprit, only then will he or she test for something rare and exotic.
Not so on TV. On your average Medical Drama, every disease is super rare, the kind that a real doctor might encounter only once in their whole career. This is partly because viewers are easily bored watching routine medical treatment and need something dramatic, partly because rare diseases can often be topical and trendy, and partly because these shows want to show that the doctor is very smart and can recognise the real cause right away. Said smart doctor is likely to lampshade the rarity of the disease.
But it happens so often on TV that there's a recurring slate of diseases that show up across different TV shows, Medical Dramas and otherwise. Such rare diseases are so common on TV, you might think they're transmitted through television. Some of these diseases are:
- Exotic allergies. While allergies are common, on TV they have to be caused by something weird. And every patient reacts to these allergies by swelling up like a blowfish — something that should be life-threatening, because that level of swelling is almost always accompanied by anaphylactic shock and the airway swelling shut.
- Congenital insensitivity to pain. Extremely rare in real life, but irresistible to TV writers, both for the gruesome results of not feeling pain and for the metaphorical implications. Seen on House, NCIS, Grey's Anatomy, All Saints, and The X-Files.
- Münchausen Syndrome, where the patient is faking illness for attention. The inherent drama of the patient fooling the doctor has made it a staple of TV. Bizarrely, on TV "Munchausen by proxy" seems to be even more prevalent than garden-variety Munchausen Syndrome; this is where a parent fakes an illness in their child to get a doctor's attention (or possibly even makes them sick for real). The proxy variant's prevalence owes itself to its popularity on crime shows; it's been seen several times on Law & Order.
- Infertility. It's far more common on TV than in real life. Chalk this one up to the Law of Inverse Fertility — on TV, the more you want a child, the more likely you'll be unable to conceive, because drama! This may also be why pregnancy complications are so common on TV, even really rare things like ectopic pregnancies.
- Genetic mosaicism, or when a person has two different genomes. It's technically not that uncommon; it's just that the genomes merge together at an early stage and it doesn't cause many problems, so no one really tests for it. It might lead to things like differently coloured patches of skin or mismatched eyes, but those are just cosmetic. On TV, though, it's as if you're a Mix-and-Match Man, with implications ranging from brain problems (House) to multiple sets of DNA thwarting the police's Rapid DNA Test (CSI).
- Multiple Personality Disorder. In real life, it's so rare that some psychiatrists doubt that it even exists. On TV, it's so common that... well, it's a trope. Insofar as it does exist, it's technically called "Dissociative Identity Disorder" (not that they remember this on TV). While on TV, there are only two "split" personalities, in real life more than half of sufferers have more than ten, and some have as many as 100.
- Porphyria, a metabolic disorder that makes your skin sensitive to light and your urine deep red. It's more common on TV than in real life for two reasons: first, the symptoms are superficially similar to vampirism, and second, George III is believed to have suffered from it (although experts are split on whether he really had it).
- Hypertrichosis, a condition that causes thick hair growth all over the body. It's more common on TV than in real life because these symptoms are superficially similar to lycanthropy, to the point that it's colloquially known as "werewolf's syndrome". Appearances include Human Nature, Fur: An Imaginary Portrait of Diane Arbus, Wolf Girl, Moon Of Desire, the "Werewolves" episode of CSI, and the "Scream Again" episode of Scream Queens (2015).
- Tourette's Syndrome, almost always depicted by the sufferer swearing uncontrollably, even though fewer than 10% of Tourette's sufferers actually do this. It's just funnier when people swear randomly.
- Asperger Syndrome, always shown on TV in its most severe form with the sufferer barely able to function, and usually with the implication that it makes you a genius. While most cases are much less severe and some are barely even noticeable, unfortunately we can't say with much certainty how prevalent it is (indeed, this is a matter of controversy), but we can say it's almost certainly less than self-diagnosing Internet Jerks claim it is.
- Easy Amnesia. It's very useful to writers, considering how it allows the character to know as much as the audience. It's either done for the drama of unlocking one's memories (where it's usually caused by a Tap on the Head) or for comedy (where it's usually cured by a Tap on the Head). In real life, it's nothing like it is in fiction. TV also tends to exclusively depict retrograde amnesia (can't remember anything before the whack) as opposed to anterograde amnesia (can't form memories after the whack), which is somewhat more common.
- "Trans Broken Arm Syndrome". This has to do with TV conventions of depicting transgender persons; for what ever reason, the reason they're seeing a doctor is always related to their being trans. Even if the issue is as mundane as a broken arm, it will somehow relate to hormones, genital reassignment, breast implants or removal, or something like that.
- Victorian Novel Disease, whose only symptoms are an Incurable Cough of Death, Blood from the Mouth, and turning you into a particularly striking Ill Girl. Often identified with tuberculosis, but in real life tuberculosis is much less pretty. Common in Victorian novels but not exclusive to them.
Indeed, the idea that common diseases on TV are rare in real life is so ingrained in the viewing audience that viewers will assume that of every common TV disease, even when it's common in real life, too — for instance, the rate of childhood asthma in developed countries can be as high as one in five.
- Black Jack does this, but much like with House, it makes a certain degree of sense - he's an incredibly skilled, incredibly expensive, unlicensed doctor - so he usually only gets hired by someone who's already failed to find relief from the general medical establishment, usually meaning rare and/or incurable diseases. (When Black Jack is around, you may as well tear the word 'Incurable' out of the dictionary...) There's always a point when rare becomes just plain made up. Lionitis is rare and highly unlikely; a telekinetic fetiform terratoma is just plain impossible (as far as we know).
- Saijou no Meii features a traumatic cardiac tamponade, one of those conditions known for turning up far more in medical dramas than real life, in the very first story. Again, somewhat excusable as the series' focus is on pediatric medicine and young children are more susceptible to it than adults because their ribs aren't fully developed.
- The Sixth Sense included suspicion of Münchhausen Syndrome by proxy. Possibly, either the doctor or the writer had been watching too much TV (or both since they were the same guy).
- Overlapping with Theater, in Repo! The Genetic Opera, we have a spectacular case of Munchausen By Proxy. It's all the more over-the-top since the individual responsible is a physician and the case has lasted for seventeen years!
- The page quote is discussed in Robin Cook's Outbreak when the protagonist experiences a lot of skepticism over a diagnosis of ebola. Similarly, Jack experiences skepticism over an anthrax diagnosis in Vector. There are probably lots of other examples since Cook has written dozens of medical thrillers.
- Inverted once on Doogie Howser, M.D.: A celebrity came in to the hospital after a trip through third-world countries with an illness none of the doctors recognized immediately. They did tests for all sorts of unusual diseases, until a nurse recognized it as measles, which wasn't recognized solely because immunizations for the disease are nigh-ubiquitous. That's Truth in Television; most doctors in recent decades have never seen an actual live case of measles.
- Seen often in House, but justified by the setting: Dr. House specializes in diagnosing rare diseases. Many of his patients have already been seen by other doctors who couldn't explain their symptoms. House seems to get quite a kick out of seeing diseases like this on a regular basis, and he dreads his clinic hours when he has to treat walk-in patients with ridiculously common diseases. He also periodically lampshades all this with the Running Gag, "It's never lupus." (Except that one time that no one acknowledges.) In fact, it would be easier to list the instances where the Patient of the Week did not have a Televisually Transmitted Disease after all:
- One patient shows up only for Foreman to diagnose him with heatstroke. Then he got progressively worse, and another doctor who specialised in third-world diseases identified it as polio — something all but unknown in the developed world. It turned out that said doctor was poisoning the patient with thallium to mimic the symptoms of polio. All this made Foreman's original diagnosis of heatstroke actually correct. After figuring out what the clearly insane doctor did, House fired him and Foreman called the cops. The episode ends with An Aesop about trusting your own instincts, and those of the guy in charge.note
- One patient is a kid who collapsed at a basketball game. Turns out he has genetic mosaicism and everyone considers it as a possibility. Turns out he was just dehydrated, and the contrast dye used for the MRI made things worse due to his impaired kidneys.
- Foreman once misdiagnosed a woman with a rare disease when she had a simple staph infection. That misdiagnosis killed the patient, and Foreman never quite got over it.
- House and Cuddy are on an airplane returning from a conference about rare, infectious diseases — and wouldn't you know it, a couple of passengers get sick with similar symptoms. Turns out they had entirely different things wrong with them; one had been scuba diving shortly before and got the bends from the air pressure change, and the other turned out to be pregnant. The doctors' intervention caused several more passengers from psyching themselves out and puking.
- As early as the pilot episode, House explains his philosophy to Foreman:
Foreman: First year of medical school: if you hear hoofbeats, you think horses, not zebras.
House: Are you in first year of medical school? No. First of all, there's nothing on the CAT scan. Second of all, if this is a horse, then the kindly family doctor in Trenton makes the obvious diagnosis, and it never gets near this office.
- The Golden Girls: Dorothy was struck with a strange illness that left her perpetually lethargic. Every doctor she saw, including a specialist in New York, told her she was just getting old and should do something new like get her hair done. But the last doctor she saw correctly diagnosed it as the rare Chronic Fatigue Syndrome. This had apparently happened to one of the producers in real life, which inspired the episode. Only problem is that CFS is a "diagnosis of exclusion", something defined by the lack of every other known cause of fatigue, and that there's no treatment — maybe getting your hair done is the best thing you could do.
- Grey's Anatomy did this so often. It featured:
- A tumor causing a perpetual Raging Stiffie, a condition formally known as priapism, and the reason those ads tell you to call a doctor if you experience an erection lasting longer than four hours.
- Repeated spontaneous orgasms, a real condition known as persistent sexual arousal syndrome. The doctors actually envy the patient for a bit before she sets them straight about how debilitating it is. It was actually less debilitating on the show than in real life; the show's patient had them ten times a day, whereas real sufferers can experience hundreds.
- Lionitis, formally craniodiaphyseal dysplasia, essentially a misshapen skull that makes the patient's face mask-like.
- Vaginal poison oak rash (be careful what you wipe with!)
- A guy whose penis got caught on the inside of his ex-wife's IUD during sex.
- Another guy who was a depressed author who ate a book. They had to remove it (or what was left of it) from his stomach.
- A pair of adults (played by the Sklar brothers) who were conjoined at the spine and both in love with the same woman. The episode went to great pains to point out how completely impossible it would have been to separate them, and then they did it anyway.
- A girl with VATER (now known as VACTERL) which affected her spine so badly it was at a 90-degree angle.
- A man who was shot in the chest at point-blank range with a bazooka and managed to survive.
- A girl who actually has XY chromosomes but is resistant to testosterone. In real life, this is androgen insensitivity syndrome, and it usually doesn't actually cause any medical problems on its own.
- A woman who had a reaction between her chemotherapy and a herbal supplement turn her blood neurotoxic.
- A 100% face transplant, so successful that the guy could take off the bandages the same day and had almost no ill effects whatsoever.
- A patient with clairvoyance. And a brain tumour.
- A nineteen-year-old encased in cement.
- A man with a pine tree growing in his lung.
- Candiru, a toothpick-like fish that lives in the Amazon River which follows ammonia trails and occasionally (and painfully) can lodge itself inside the penis. Guess where they found this one.
- Necrotizing fasciitis, commonly known as "flesh-eating bacteria". Not actually that rare (even Scrubs did it at least three times), but not quite as dramatic as this show has it.
- A super-fat man who dies of his super-fatness.
- A woman with two uteruses. It can happen (it's called "uterus didelphys"), but usually the patient is not pregnant with two different children from two different men at the same time.
- A woman pregnant with quintuplets.
- A woman who was rendered amnesiac and bruised beyond recognition by a giant pylon falling on her face. And she's also pregnant.
- A man who was rendered bruised beyond recognition and lost all motor skills after pushing a girl out of the way of a bus and getting hit himself. This makes it hard for the doctors to see that it's actually George.
- A woman rescued from a body of water who's been legally dead for several hours from drowning and hypothermia but recovers. This can happen in real life — EMTs are trained on care for such patients. But in this case, she doesn't even suffer any lasting effects (perhaps because she's the eponymous character).
- A woman with skin cancer that's spread to her brain and causes hallucinations of a dead love, and who's also Izzy. The main characters certainly provide their friends with a lot of practice.
- One episode of Lie to Me had a suspect with Dissociative Identity Disorder, correctly named and handled with slightly more accuracy than most places. For someone it was called "the holy grail of psychology".
- M*A*S*H didn't do this too often; although it was technically a medical show, it was set in a war zone, so most of the patients they saw had war-related injuries. The most "uncommon" diseases the unit encountered were haemorrhagic fever and malaria; in the latter case, both Klinger and another corpsman had a reaction to the anti-malarial medication they were issued.note
- Partially deconstructed as part of a B story in the short-lived FOX series Mental. The father of one of the doctors plays a doctor on television and, mimicking his acting job, diagnoses a patient with Mad hatter disease and orders a blood test on her. The real doctor is annoyed at his father practicing medicine without a license... until a nurse comes in and asks how he made the connection, as the disease is really rare.
- Scrubs tended to lampshade the phenomenon, usually contrasting the naive JD with the more experienced Dr. Cox:
- JD diagnoses a patient with Kuru, a disease confined to Papua New Guinea and transmitted by cannibalism. Dr. Cox berated him for exactly this trope (in his typical Coxian way). Indeed, the disease turns out to be mundane, and even the patient himself makes fun of JD.
- JD suspects another patient has SARS. Not only does he not have SARS, but the hospital is now required, based entirely on JD's suggestion, to quarantine everyone — who's now unfathomably pissed at him.
- When a news broadcast starts freaking out about two Hepatitis A cases, the hospital gets overrun with people who think they have it. Cox pretty much says it happens every time:
Dr. Cox: And you know what happens next? Every hypochondriac with the sniffles is gonna come thundering through those doors. So enjoy the next few days of peace and quiet.
- Sisters: Both Frankie and Teddy were diagnosed with infertility, even though Teddy had already had a daughter. And Teddy also picked up temporary "hysterical" blindness after seeing her husband die from a car bomb and for no physical reason, something that's pretty much unheard of in real life.
- As stated under Film, in Repo! The Genetic Opera, we have a spectacular case of Munchausen By Proxy. It's all the more over-the-top since the individual responsible is a physician and the case has lasted for seventeen years!
- Jeff Foxworthy hangs a lampshade on it, retelling his wife's over-reaction every time she sees an article about a disease on 60 Minutes.
Jeff's Wife: I got it... I have every one of those symptoms!Jeff: You do not have testicular cancer! You don't even have testiculars!
- The Dragon Doctors were formed specifically to treat rare diseases — magical diseases. The author has been quoted as saying that since quite a lot of medical dramas just plain make up their ailments, he might as well not bother setting it in the real world. The solutions are always presented in a logical fashion, however.
- Often parodied in The Simpsons:
Homer: Oh, why me?!
- In 'The Mansion Family," Mr. Burns was diagnosed with every disease.
Doctor: Mr. Burns, I'm afraid you are the sickest man in the United States. You have everything.
Mr. Burns: You mean I have pneumonia?
Mr. Burns: Juvenile diabetes?
Mr. Burns: Hysterical pregnancy?
Doctor: Uh, a little bit, yes. You also have several diseases that have just been discovered - in you.
- In "Blood Feud," Bart's allergies include both butterscotch and imitation butterscotch.
- The children tend to choose the rarest diseases to falsely call in sick and skip school, like leprosy (Nelson) and spontaneous Tourette's (Bart). Of course, this arises suspicions. The latter episode ends with Bart surviving a wolf attack but having to deny it because Krabappel won't believe him.
- In another episode, Lisa makes Bart and Homer believe they have leprosy in an attempt to Scare 'Em Straight and help clean the house, but all she achieves is to have Flanders send them to a leper colony in Hawaii.
- In "The Homer they fall", Dr. Hibbert diagnoses Homer with "an absolutely unique genetic condition known as Homer Simpson Syndrome", which shields him from feeling most hits to his head.
- In 'The Mansion Family," Mr. Burns was diagnosed with every disease.
- The Venture Bros. invokes and lampshades this trope in "The Diving Bell vs. the Butter-Glider". When Dr. Venture is unconscious and partially paralyzed, Billy Whelan and Pete White are called in to treat him. Billy immediately points out that the most obvious diagnosis is a stroke, but he also white-boards all manner of other exotic possibilities, including "lazy face", but drawing the line at "gum swallowing".
Pete White: He's hooked on House. We both are.