A classical NotWhatItLooksLike scenario; Alice walks in Bob's room, sees Bob injecting something in his arm with a syringe. Assumptions are made, and conclusions jumped to, until Bob reveals that he's diabetic and was taking his insulin shot. May be played for drama or for comedy.

Pills and powders are also often mistaken for recreational drugs. Sometimes Mistaken for Junkie is used to criticize the DrugsAreBad hysteria.

Unfortunately TruthInTelevision, and some groups are almost guaranteed to have encounters with it: diabetics, as mentioned, (due to the need for insulin injections); transgender people (due to the need for hormone injections and the status of androgens/testosterone and some estrogens as controlled substances); nocturnals or those with sleep phase disorder or those with hyperthyroidism as users of illegal stimulants (due to different sleeping patterns, and in the latter two, behavior that sometimes resembles stimulant users). Anyone who frequently has to have IV injections or blood work done will almost always get this, especially if they were unlucky enough to have encountered someone doing the injection/blood work so improperly as to give them a track mark. Legitimate pain patients and those legitimately taking a lot of psychotropic medications for mental illnesses are also often assumed to be junkies, because they're taking lots of pills/other medications, never mind that is to keep them alive and (somewhat) well.

See also MistakenForSubculture. Contrast PlayingDrunk, where a character ''deliberately'' misleads others to think this.



[[folder: Fan Fic]]
* Parodied by FoxxFireart in his/her [[http://foxxfireart.deviantart.com/art/Code-Geass-Refraining-87013589 Code Geass fan-comics]]. In R2 when [[spoiler: Lelouch is going to use drugs to escape from his depression]]
* In the serious AU of ''Comicbook/CaptainCarrotAndHisAmazingZooCrew'' "[[https://www.fanfiction.net/s/673833/1/Amazing-Zoo-Crew-The-Harmony-Trap The Harmony Trap]]", one of the characters is a dog who used to be a policeman and has diabetes which he tried to keep secret. It's mentioned that Internal Affairs catching him with needles was the worst moment of his life, although he was easily able to prove that it wasn't what they thought it was.
* PlayedForDrama in ''FanFic/TheRiseOfDarthVulcan''. As a result of Princess Luna including vampire bats in their genetic makeup, thestrals literally must drink blood to survive. But the rest of the ponies found this icky, so they made up some nonsense about the blood hunger being a mental disease, banned the drinking of blood, and forced the thestrals to use an alchemical substitute that keeps them all borderline starving. Needless to say, Luna was ''furious'' when she found out that Celestia had endorsed all this.

[[folder: Film]]
* In ''Film/PrettyWoman'', when Richard Gere enters the bathroom and finds Julia Roberts apparently swallowing something, he thinks she's popping drugs, when in fact she's just flossing her teeth.
* In ''Film/MadMoney,'' two of the protagonists see the third's syringes fall out when she drops her purse. They give her a mini-lecture on drugs, but of course it turns out she's simply diabetic. Except in this case she never tells them.
* In the Creator/DisneyChannel film ''Film/GoFigure'', Shelby runs off after being berated after falling and messing up her routine. Caitlin follows her into the bathroom and sees a syringe fall under the stall, and she begins to lecture her on drugs. Shelby tells her that she's diabetic. And then they go get sugar-free frozen yogurt.
* In the Marlon Waynes movie ''Film/{{Senseless}}'', Waynes' character is using an experimental drug to enhance his senses to superhuman levels (in order to both get the girl and win a coveted business internship). His roommate walks in on him after he's given himself an injection, sees the needle, and (based on this and Waynes' erratic behavior) assumes that he's gotten hooked on heroin. Eventually Waynes' character explains what is really going on to his roommate, but its not clear if he really believes him; during the big confession scene during the climax as Waynes reveals that he's been using a drug to get an advantage in the competition for the internship, the roommate interrupts him to announce that "[[SuspiciouslySpecificDenial It's NOT heroin!]]"
* Subverted in the film ''Film/BodyOfEvidence''. The murder victim's secretary claims to have seen his girlfriend (and suspected killer) snorting cocaine. When her lawyer confronts her about this, she reveals that the white powder was an herbal medication for menstrual cramps. Later it turns out that she did in fact use cocaine and that what the secretary assumed was probably correct.
* Happens to the titular ''Film/BadTeacher'''s rival when she becomes determined to prove her (correct) suspicions that among other things, the woman is a drug abuser. To that end, she switches desks with the woman so as to search through the drawers ([[IdiotBall rather than just merely leaving it in the room to look through it there]]) and finds drug paraphernalia. Unfortunately, by now, the other woman is on to her and is able to sic the authorities on ''her''. Between this discovery and her previous erratic behavior (which is ''also'' due to her efforts to prove what a wretch the other woman is), ''she'' is the one to get fired for drug use.
* Mia in ''Film/EvilDead2013'' was once a junkie, and her friends brought her to [[DontGoInTheWoods a cabin in the woods]] as part of an intervention. When she gets [[DemonicPossession possessed by a demon]], her friends initially write off the signs of her possession as a case of her going through withdrawal. It's only with her possession [[TheCorruption spreads]] to the rest of the group that they realize it has nothing to do with drugs.
* In ''Earth vs. the Spider'', Stephanie sees a track mark on Quentin's arm, and assumes he's been shooting up. He explains to her that he was ''accidentally'' injected with a serum that gives him spider powers.

[[folder: Jokes]]
* One of Creator/GeorgeCarlin's stand-up routines invokes a variation where the "mistake" isn't exactly sincere:
-->If a policeman really wants to give you a hard time, he can hold you overnight while they check the vitamins. That's why I travel with ''[[WesternAnimation/TheFlintstones Flintstone]]'' vitamins!

[[folder: Literature]]
* Only a partial example since Literature/SherlockHolmes actually ''is'' canonically a drug addict, however, there's one particularly amusing scene in "The Adventure of the Missing Three-Quarter" where Watson walks in on Holmes filling a needle ''[[OutOfCharacterMoment during a case]]'' and panics. It turns out that the solution is really aniseed oil, with which Holmes marks a carriage so that Watson's dog can follow it.
* One of the ''Literature/TheBabysittersClub'' books featured this, in which diabetic Stacey had trouble getting her insulin kit past security at a concert.
* One of the plot points in the YA series-pulp book ''The Real Deal: Unscripted.''
* There's a variation in one of the ''Trace'' novels by Warren Murphy. A bigtime movie star travels with a doctor who gives him pills on a regular basis. The movie star acts like these are some kind of "happy pills", but the doctor later reveals that the star is in poor health and all the pills are actually medically necessary.
* One of the subplots in''The Help'': Minny walks in on her boss, Celia, sitting on her bed with a dozen bottles of what appears to be homemade alcohol, and believes she's discovered that Celia is a closet alcoholic, which repulses her. When she finally confronts Celia about it, Celia tells her that it was actually a "tonic", a home brew she'd turned to in a desperate attempt to carry a pregnancy to term after a series of miscarriages.
* Briefly done in Dan Brown's ''Literature/DigitalFortress'', where David Becker mistakes a DistressedDamsel at the airport for a drug addict. As he tries to help her, he is in turn MistakenForPedophile, making this twofer.
* In a ''Literature/SweetValleyHigh'' Christmas edition, Jessica snoops through the personal belongings of their houseguest (she hates the girl and has become suspicious of her behavior) and concludes that she's a drug addict based on the number of pill bottles that she finds. In reality, the girl is ill and the pills are her medications. (And there is no way that the bottles wouldn't have been labeled. Even as a high school student with no medical education, it's unlikely that Jessica couldn't have realized that these were medicines, not illegal substances).
* In ''[[Literature/TheBloodLadders An Heir to Thorns and Steel]]'' Morgan's seizures get so bad that his doctor prescribes opium. But the first time he takes it he gets the dosage wrong and his friends see him stoned and assume his emaciated figure is a sign of long-term addiction, since he tried to hide his illness from them. Eventually they talk to his doctor, who shows him how to dilute it properly too.
* Curt from ''Fat Kid Rules The World'' is extremely skinny, doesn't wash his hair often, is referred to as "semi-homeless", and wears dirty, damaged clothing. He gets mistaken for a drug addict but he doesn't use drugs.
* In ''[[Literature/TheRedVixenAdventures Shadow of Doubt]]'' Alinadar is seen injecting herself by a maid, whom she threatens to not tell. [[spoiler: She used to be a ChildSoldier and her "owner" got her addicted to combat stimulants, she's currently taking a prescription agonist to mitigate the withdrawal symptoms and is ashamed of it.]]

[[folder: Live Action TV]]
* ''Series/HomeAndAway'':
** Happened once with the insulin shot.
** Happened again, with pills this time around. It's understandable, however, as Belle actually ''was'' a junkie for the first half of 2009.
* A variant with Estrogen shots in the BBC drama ''Series/TheFamilyMan''.
* ''Series/DarkAngel'':
** Max was caught taking a supplement that stopped her seizures and her roommate thought it was drugs, so she flushed the pills.
** Max herself entered the exact moment a prostitute was injecting herself and received a very casual "I'm a diabetic, this is my insulin shot" right after the woman noticed her presence.
* ''Series/{{House}}'':
** There's a scene which fits this: the title character is snorting a white powder, and it turns out to just be antihistamines for his cold.
** In one episode House stopped taking his vicodin and appeared pain free. His colleagues deduced he had started heroin but he had actually turned to methadone.
** This trope is what actually attributed to the loss of House's leg muscle. He was in obvious huge amounts of pain, injected himself in the thigh with demerol, the Doctors thought he was just an addict and sent him home. And you know what happened next...
* There's an example on ''Series/JonathanCreek'' where something like this is pulled on the audience - we see the girl pull out a syringe early in the episode, leaving us to assume she's a junkie. Later she does the same thing, but it's quickly confiscated by her aunt. [[spoiler:Her aunt is the murderer, and is trying to kill the girl (who is diabetic) by locking her in a room without her insulin after she discovered a tape she used to make the (blind) victim jump out of the window, thinking there was a fire.]]
* An episode of ''Series/PeakPractice'' has a homeless diabetic who everyone assumes is the mother of an abandoned child. At one point she gets all her insulin supplies destroyed by a group of yobs.
* Potential inversion twice in ''Series/CardiacArrest'' reminding us that insulin is actually a very dangerous chemical. First when someone injects themselves with an overdose as a suicide and second when a deranged diabetic injects a doctor with his own insulin. [[spoiler: The series ends with the doctor, who is the main character, being carried into the operating theater after preliminary treatment on a couch.]]
* The wonderful episode of ''Series/{{Seinfeld}}'' where Elaine tests positive for opium as a result of eating too many poppy-seed bagels. [[TwoLinesNoWaiting Meanwhile]], the showerheads in Jerry and Kramer's building have been changed to a low-pressure model, and they're so desperate for a decent wash ("[[DoesThisRemindYouOfAnything I feel like I have little bugs crawling all over me!]]") that they end up furtively buying new ones from a shady guy with a van.
** [[HilarityEnsues And Kramer buys "the one designed for elephants"]].
** Appears to be a case of TruthInTelevision since ''Series/MythBusters'' proved that eating poppy seeds actually can register a positive for opium with some drug tests, in spite of the fact that there are only trace amounts in the poppy seeds used for cooking.
** Another ''Seinfeld'' is entitled "The Sniffing Accountant", and you can probably guess that one from the title. (It turns out to be an allergy to mohair... until it turns out it actually is drugs).
* In ''Series/{{That 70s Show}}'' Eric's parents thought that he's on drugs when he started acting weird; actually, he [[PrimalScene saw them having sex]].
* When Series/{{Dexter}} is caught in his web of lies at one point and thinks he is going to be exposed as a [[SerialKillerKiller serial killer]], instead it is assumed that he is a drug addict. [[SureLetsGoWithThat He goes along with it]].
* On ''Series/{{Webster}}'' the reason George doesn't want Webster's uncle played by Ben Vereen to have custody of him. He saw his syringe in Webster's parents' bathroom years ago and assumed he was shooting himself up with heroin. It turns out he's diabetic.
* Meta example: Everyone wanted to know what was up with that syringe Inara in ''Series/{{Firefly}}'' was holding. Joss assured the public at large that it wasn't a suicide shot or some kind of narcotic (the closest to actually confirming what it ''was'', was implying that a second season of the show would have explored some sort of illness on Inara's part).
* ''Series/{{Neighbours}}''. After seeing Danni Stark inject insulin for her diabetes, Michael Martin spreads a rumour that she is using drugs. She goes along with it to get attention.
* In the second season of ''Series/{{Everwood}}'' Delia Brown walks in on Linda Abbott taking a lot of pills in their bathroom. She tells Linda she "thought she was a junkie" when she finds out she was actually [[spoiler:Taking medication to maintain control of her HIV.]]
* ''Series/{{CSINY}}'' Hawkes, after his girlfriend took him to a party where pot was being used. He was around the smoke long enough that he got the residue in his system and it showed in his random NYPD drug test. It wasn't enough to get him fired, though Mac called him on it.
** A similar thing happened to Delko in ''Series/CSIMiami'', except it was his sister (who was taking it for medical reasons) and him testing positive (along with a few other things) convinces an IA agent that the lab's corrupt [[spoiler: causing her to try and plant evidence to [[FramingTheGuiltyParty "prove"]] it]].
* On ''Series/{{Degrassi}}'', when Marisol is planning a trip for her and her boyfriend Mo and needs to fill out a travel insurance form, he won't let her fill it out for him. She gets paranoid and goes through his bag, finding needles. Marisol assumes that he is a junkie (despite the fact that she doesn't even know what drug uses needles) until she finds out he's diabetic.
* One episode of ''Franchise/{{Emergency}}'' had a know-everything former combat medic training to become a paramedic. The patient he insisted was on an acid trip turned out to be a diabetic with dangerously low blood sugar, who would have died if Roy and Johnny hadn't given him glucose.
* ''Series/{{ER}}'':
** A similar scene occured when a young man was rushed into the hospital with chest pains. Dave Malucci assumed he was having a cocaine-induced heart attack, despite his brother insisting that he didn't use drugs, as well as a ''negative'' toxicology screen. To that end, he browbeat his senior doctor into giving the man a thrombolytic (a clot-dissolving drug used in the treatment of heart attacks and strokes)--which killed him because the man wasn't having a heart attack, but an aortic dissection.
** Also a scene in which Kerry Weaver is caught using a hypodermic needle clearly has some of her coworkers worried about this, given her recent erratic behavior. It turns out she's taking hormones to boost her fertility.
** And another in which Carter becomes suspicious when he notices Lucy taking pills and then having a clearly more upbeat demeanor than before. When he confronts her, it turns out that she ''is'' using amphetamines--prescribed by her doctor for treatment of ADHD.
** A year later, this is completely inverted with Carter, whose mood swings and erratic behavior are attributed to post-traumatic stress following his attack. It turns out he's addicted to painkillers.
* On ''Series/LawAndOrder'', detectives view video footage of their murder victim staggering around while at a party. They assume she was drunk, but the autopsy reveals that she received a head injury and was suffering from intracranial bleeding.
* ''Series/StrongMedicine'':
** ''Strong Medicine'' possibly ripped off the ''Emergency'' example cited above when one of Lu's patients is arrested for drug use, perplexing her as the woman has no history of this. It turns out that she's a diabetic who took too much of her insulin, resulting in symptoms that mimicked a PCP overdose. While testifying, Lu surprisingly sides with the cops after admitting that even a doctor would have trouble distinguishing the difference without running the proper tests, much less a layperson.
** Also, when Dr. Dylan West follows his patient to where she buys her supply of heroin (he's trying to help her quit), the cops show up and arrest them both, not believing his explanations. The entire time he's in jail, he becomes very edgy, twitchy, and ill, making viewers wonder if he really does have a drug problem of his own, only for him to be seen injecting himself with insulin, revealing that he himself is a diabetic.
** And when the staff is subjected to drug testing. Peter is worried that he might test positive given his occasional pot-smoking. He doesn't, but Lana tested positive for ''cocaine'', stunning her as she had long since given up that lifestyle. It turns out the medium used for testing--human hair, because toxic substances can linger in the hair long after a person has last used the drug--could also easily pick up outside substances. Lana lived in a poor neighborhood where drug use was frequent and the cocaine particles in the air had clung to her hair (and it being African-American hair made them even more likely to stick than to hair of a different ethnicity and texture), making her test positive even though she no longer used drugs.
* ''Series/ThirdRockFromTheSun'' [[InvertedTrope inverts]] this hilariously with Sally finding bags of cooking herbs in Tommy's sock drawer and the family confronting him about his hidden [[SupremeChef cooking skills]]. Tommy tries to cover it up by saying it's pot.

[[folder: Music]]
* The Suicidal Tendencies song "Institutionalized" has its focus character get sent to an institution partly because of this trope.

[[folder: Newspaper Comics]]
* In one ''ComicStrip/{{Zits}}'' strip, Walt is suspicious when Jeremy start burning incense in his room. Thinking it is to cover up the smell of pot smoke, he bursts in to discover Jeremy is using it cover up the smell of him cooking waffles.

[[folder: Religion]]
* A few instances from ''Literature/TheBible'':
** In ''[[Literature/BooksOfSamuel 1st Samuel]]'', Hannah's impassioned prayer (doing so almost silently) is mistaken for drunken ramblings by Eli, a head priest. However, the last chapter or so has made it clear that the behaviour Eli suspected was common at this time. He probably caught more than one person wandering into the temple drunk, and was making an innocent mistake.
** Similarly, in ''[[Literature/ActsOfTheApostles Acts]]'', the disciples are mistaken for drunk during the Pentecost, when the Holy Spirit pours out the gift of tongues on them. Sadly, there are preachers who ran with the idea that Peter and the other apostles were actually "drunk in the Spirit" based on a misinterpretation of Peter's defense, "For these are not drunk, as you suppose, since it is only the third hour of the day," (Acts 2:15) and hopscotching it with Paul's admonition in Ephesians 5:18 to "do not be drunk with wine, in which is dissipation; but be filled with the Spirit." In this case, they are being Mistaken (by the very readers of Scripture) For JunkieProphet.

[[folder: Tabletop Games]]
* Played for horror in one of ''TabletopGame/HunterTheVigil'''s NPC monsters. [[spoiler:A Changeling who is constantly shivering is assumed by her coworkers to be an addict, when in fact it's because she has an icicle stuck in her heart.]]

[[folder: Video Games]]
* A tragic example in ''VideoGame/FalloutNewVegas'' with Vera Keyes. Her partner in crime finds out that she has been making heavy use of narcotics and painkillers, and blackmails her into helping him. Technically it's true that Vera is indeed on all of those drugs.... but the reason is that she's terminally ill and her condition causes her severe chronic pain. She doesn't want anyone to know she's dying, so she takes drugs secretly to manage her symptoms.
* One of the subplots that appears in Unisys game ''A Week in the Life of...'', where a character notices someone else taking an insulin injection.
* In ''VideoGame/Persona4Arena,'' [[VideoGame/{{Persona 3}} Akihiko's]] tagline is "The Two-Fisted Protein Junkie" because of his insistence on a fighter's need for protein drinks. A South American bartender gets the wrong idea when Akihiko asks for a fix and mentions withdrawal.
* ''VideoGame/BeyondTwoSouls'': During the "Homeless" chapter, Stan assumes Jodie is a drug addict after she has a ghost-related freak-out. She has to assure him that she's not.

[[folder: Visual Novels]]
* Goes badly in ''VisualNovel/KaraNoShoujo'' when Mizuhara Toko mistakes her friend Kuchiki's medication for drugs - and gets rid of it. This means that Kuchiki is without it when her condition begins to act up [[spoiler:and deliriously wanders into traffic where she passes out and gets hit by a truck]].

[[folder: Webcomics]]
* One ''Webcomic/SaturdayMorningBreakfastCereal'' plays with this - the situation is a woman being held back from a syringe, and we assume she's on some sort of illegal drug. Then it turns out it's insulin. [[spoiler:Double Subversion: she's not diabetic.]]
* In a story arc of ''Webcomic/SandraAndWoo'' the girl Larisa is caught by a teacher when giving herself an insulin shot during recess. The initial confusion was logical enough, since Larisa did play up the "junkie" image for a laugh, but even after being informed that she literally needs it to live, the principal continues insisting that taking this "dangerous drug" violates the school's zero tolerance policy against drugs. The plot was inspired by a [[TruthInTelevision similar incident on a U.S. middle school in the 1990s]]. [[http://www.sandraandwoo.com/2009/05/18/0060-addicted/ Start reading here.]]
* In ''Webcomic/{{Shiniez}}'' Ally's neglect of her day to day life during her relationship with Alan caused her mother to make this mistake when in reality she was addicted to the BDSM.
* In ''Webcomic/{{Runners}}'' the planet Ciceron has a huge [[FantasticDrug crush]] problem, which Keyla attempts to solve by finding a cure for the addicts. When her father finds out she's been trying to get her hands on some crush, he's [[TearJerker devastated]].
* A ''Transe-Generation'' comic has a trans man's testosterone injection mistaken for a drug.

[[folder: Web Original]]
* Merry managed to pull this off to a transit cop in ''Literature/WhateleyUniverse'' while not even being caught taking anything. This was accomplished through a combination of migraines, hunger from increased mutant metabolism, and being homeless and traveling by tunnels at the time.
* In ''{{WebVideo/Kickassia}}'', after a particularly over the top LargeHam moment:
-->'''Linkara:''' Are you HIGH?!
-->'''Angry Joe:''' *Demented smile*
** In ''WebVideo/SuburbanKnights'', Bill, who really does seem to be TheStoner, reacts this way to what [[BigBad Malecite]] says.
---> "Dude, what are you high? Cause I totally want some."

[[folder: Western Animation]]
* ''WesternAnimation/TheSimpsons'':
** In an episode where Marge and Homer reminisce about college days; Homer had become a grunge rock star, but due to Marge dating her teacher he had become withdrawn and depressed. He wrote a song for her (a parody of "Glycerine") and when she saw it she went to go get him back: She found him with a syringe in his arm. When she went to pull it out, Homer cried "But I need it!". Turns out it was insulin, as Homer became diabetic from drinking too many Starbucks Frappacinos, He really did need it.
** She does this again with Bart when he gets into a trading card game and she mistakes him for a dealer.
* In ''WesternAnimation/BatmanBeyond'' Terry's mom jumps to conclusions upon finding suspicious looking patches in her son's bag. To her credit these ''were'' drugs, a steroidal compound known as "slappers," but Terry was bringing them to [[Franchise/{{Batman}} his boss]] for analysis. Terry's (entirely truthful) excuses don't help: "They're not mine! [[HoldingItForAFriend I found them]]!"
* ''WesternAnimation/SouthPark'':
** The episode "Major Boobage" does this with cat urine. When Kyle's dad Gerald finds out, he freaks out and latches onto both the JerkassBall and the VillainBall by having cats banned from South Park. For some reason, while the boys were trying to help Kenny get over his cat urine addiction, Kyle decides to take a cat home. Bad idea, because Sheila finds it in his drawer, and it leads to a conflict between Kyle and his parents, who accuse him of being a smuggler and punish him without any explanation. [[spoiler:Shortly after, it turns out that Gerald was an addict himself, hence why he stupidly banned the cats]].
** Again, in the episode "Ladder to Heaven":
-->'''Congressman:''' Are you high or just incredibly stupid?
-->'''President Bush:''' I assure you [[ITakeOffenseToThatLastOne I am not high!]]

[[folder: Real Life]]
* During the Sydney Olympics a cleaner received a needle stick injury whilst cleaning an Australian athlete's room, but the needle turned out to be for a vitamin shot.
** This is a real pain in the ass for monitoring cyclists as many top athletes will inject themselves with vitamins in between races to recover faster. The equipment is nearly identical to what you would need to dope your blood or do EPO.
* If somebody is having to either have a massive number of blood-draws or injections -- or both -- for medical reasons, they might actually have to carry around a card or other paperwork verifying that the tracks are all perfectly legitimate. In particular, the Red Cross can issue cards to verify why a frequent donor might have suspicious looking scars.
* Not quite following the trope as straight as others, but pretty close: When somebody is taking medication for mental illness, many people (especially people such as MoralGuardians and TheFundamentalist) tend to think that it's as if they were taking something recreationally. This can lead to embarrassment and awkward situations.
** Doubly so if it's a [[ChurchOfHappyology Scientologist]], as they view the two as one and the same. Since its inception, the Church of Scientology has held that psychiatry is nothing more than a crooked racket of drug-pushers (it was one of Creator/LRonHubbard's big {{Berserk Button}}s, as psychiatrists were instrumental in opposing his Dianetics self-help system), and therefore, people who use medication to treat mental illness are junkies who are kept addicted by their greedy doctors. Creator/TomCruise infamously landed in hot water for this when he criticized Brooke Shields for taking antidepressants.
* Epileptic seizures can come across like drunkenness or drug intoxication to an untrained observer, especially because someone unfamiliar with epilepsy most likely equates "seizure" with grand mals (in which one collapses) and not with a petit mal seizure (which involve a general 'spacing out') or temporal lobe seizures (with mood swings and hallucinations).
** Epileptics take a wide range of drugs and they come in both pill and injected forms.
* Diabetics undergoing insulin shock/hypoglycemia often appear drunk. It's actually a medical emergency. Similarly, ''hyper''glycemia can be mistaken for someone being on amphetamines.
** Similarly, many diabetics don't like checking their blood sugar (which requires a pinprick on the finger or arm) or taking insulin in public because of this trope. Many diabetics choose to do it in the restroom or another more private place to avoid stares and questions.
* Others who can appear drunk are those with a head injury--slurring, staggering, etc.
* Can happen in some contexts with some illnesses: the more severe or stereotypical the symptoms are, the more likely someone is to be MistakenForJunkie, ''even if their illness is real.'' Common with several pain syndromes and chronic pain disorders and ADHD - the medications needed to treat them are usually addictive and controlled substances, and the more stereotypical or "over the top" the symptoms are (or, alternately, the more subdued) the more likely the diagnosis is to be missed or dismissed.
** It doesn't help that some people actually ''do'' abuse drugs by tricking or suborning doctors into writing medically unjustified prescriptions, thus setting the stage for genuine sufferers to be mistaken for drug-seekers.
* Hyperthyroidism and hypothyroidism are both very bad for this. Someone severely hyperthyroid will sometimes appear for all intents and purposes to be on something like methamphetamine or similar because the symptoms of severe hyperthyroidism can come across very similarly to those of meth addiction. Hypothyroidism, on the other hand, can present similarly to someone drugged up on sleeping pills or opiates with its tiredness, sluggishness, and similar.
* Because testosterone is a steroid, and therefore a controlled substance in many countries, FTM transgender people often have to deal with this - especially if they use injections or gel instead of implants, and are often advised to keep a copy of their prescription and/or a letter from their treating doctor.
** This also led to quite nasty transphobic discrimination against FTM athletes for a long time - seeing as testosterone is, obviously, a banned substance in most organized athletics, and there ''were'' cases of female non-transitioning athletes doping with it, FTM persons (or even women ''mistaken'' for them such as Caster Semenya) were often disqualified from organized athletic competitions or otherwise forced to "prove" their female gender and that their body was naturally producing any excess of testosterone. This situation is slowly beginning to change with some sports accepting transmen who have legitimate proof they are indeed transitioning to male and whose testosterone levels are within the cisgender male range, but still lingers on in others.
** The assumption that transgender (whether FTM or MTF) people are "on drugs" or "more likely to use drugs" also leads to discrimination in many other contexts: for example, some people will refuse to room with/rent property to/work with transmen or transwomen because of this assumption. In some places and some settings, laws have been written to make this discrimination illegal, but in many other places there isn't a law against discriminating against a transgender person, and even if there is a law, ''especially'' if the bigot can play it off to "I think they're on drugs," rather than outright trans hate, it's incredibly hard to do anything about it legally, because discriminating against ''drug users'' is codified into the law itself and heralded as a good way to reduce drug use.
* Patients who have a medically managed addiction, even though the addiction is a side effect of treatment and not being a "junkie," due to being the FunctionalAddict and having a steady, managed supply, are often written off as junkies because they are addicted - never mind that addiction is a medical process as much as it is a mental one, and someone can be ''physically'' dependent on, say, pain medication to treat chronic pain while not using it for recreation.
* In a non-drug variant, anytime a musician appears with powder on their clothes, they will almost automatically be assumed to be using drugs - even if they had just eaten something with powdered sugar on it or it's face powder from freshening stage makeup.
* A certain brand of catnip mouse decided to package the catnip separately and give you a little extra to restuff the mouse with, in a clear plastic tube with a black twist top at the end. People then come in to your house to find a crushed, dried green plant in a suspicious looking tube on your counter. Hilarity ensues.
* Certain groups of people are automatically assumed to be junkies by the majority of others, regardless of evidence or lack thereof. Prostitutes are assumed to be doing their work for the drugs, and the homeless are often assumed to take drugs since they probably up to no good anyways, at least as far as "upstanding" citizens are concerned. While these groups certainly do have members that take drugs, many do not, and the stereotyping just further isolates them from success and acceptance in society.
* Poppy-seed muffins and cakes ''do'' contain trace amounts of opium; not enough to affect the human body, but just barely enough to make a person test positive on a drug test. At least the cheap, off-the-shelf drug tests; more advanced ones are able to tell the difference. Either way, one should be advised not to eat poppy seeds on the day of the drug test, just in case. Confirmed by the Series/MythBusters.