# Can you pass out from a single drink? **URL:** \ **Category:** Factual Questions\ **Tags:** liquor-alcohol\ **Created:** [January 29, 2025, 3:03am UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560 "2025-01-29T03:03:48Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [January 29, 2025, 3:03am UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/1 "2025-01-29T03:03:48Z")
There’s a memorable scene in _Back to the Future: Part III_ where a sober Emmett “Doc” Brown downs a single shot of whiskey and promptly falls unconscious. The bartender, having seen this happen once before, observes that Doc isn’t a man who can hold his liquor. Now obviously, that scene is played for laughs. But in real life, is it conceivable for an adult’s natural alcohol tolerance to be so low that consuming even a single drink would make them pass out pretty much immediately? I’m not talking about interactions with therapeutic or recreational drugs—I’m sure that if you’re on a high enough dose of depressants like tranquilizers or opioids, adding alcohol into the mix could produce a severe and sudden reaction. I’m likewise sure that drinking while your body is undergoing severe physical stress, such as sleep deprivation or a major injury or illness, could knock you out. What I’m asking about is the possibility of a healthy, sober adult, under normal conditions, passing out after a single standard drink. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [January 29, 2025, 3:13am UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/2 "2025-01-29T03:13:41Z")
If he were truly that sensitive, he wouldn’t be able to eat yeast raised bread. It can be up to 1.9% alcohol. > **[Why Isn't Bread Alcoholic?](https://www.forbes.com/sites/quora/2017/08/03/why-isnt-bread-alcoholic/)** > > If beer and bread use almost the exact same ingredients (minus hops) why isn't bread alcoholic? This question was originally answered on Quora by Josh Velson. He would have to get passing out drunk on the alcohol absorbed in the act of drinking. ---
**Author:** ![jackdavinci](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackdavinci/32/3259_2.png) [@jackdavinci](https://boards.straightdope.com/u/jackdavinci)\ **Post date:** [January 29, 2025, 3:28am UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/3 "2025-01-29T03:28:37Z")
I don’t think it would be possible for a healthy adult to pass out just from low tolerance. People used to give kids a small amount of alcohol and they had both no tolerance and low body mass. Alcohol gets absorbed directly into the bloodstream and stays in effect until the liver processes it. “One standard drink is sufficient to almost completely saturate the liver’s capacity to metabolize alcohol.” So maybe if they had a bad liver, or one of the diseases that cause alcohol intolerance. Or low blood pressure. Also, that whiskey from the movie could have been everclear. ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [January 29, 2025, 3:47am UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/4 "2025-01-29T03:47:31Z")
> [@running\_coach](#): > > If he were truly that sensitive, he wouldn’t be able to eat yeast raised bread. It can be up to 1.9% alcohol. A shot of whiskey, which can be downed in less than a second, has about 14 grams of alcohol. To get the equivalent amount of alcohol from bread, you’d need to scarf down about 750 grams of it. I doubt the occasional sandwich poses any trouble for Doc. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [January 29, 2025, 3:57am UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/5 "2025-01-29T03:57:53Z")
But he couldn’t actually absorb the entire 14 grams in just a few seconds. I just timed the scene, he took just under 5 seconds. He couldn’t possibly have absorbed more alcohol in that time than what exists in bread. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [January 29, 2025, 4:02am UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/6 "2025-01-29T04:02:30Z")
> **[Absorption of Ethanol Alcohol](https://www.tkevinwilsonlawyer.com/library/absorption-of-ethanol-alcohol.cfm)** > > Alcohol is absorbed all throughout the gastrointestinal tract. Peak blood alcohol concentrations are achieved in as little as 30 minutes or as much as 6 hours. > Alcohol is absorbed into the bloodstream all throughout the gastrointestinal tract. A small amount of absorption can take place in the mouth, although this amount is generally insignificant because residual alcohol leaves the mouth quickly. After alcohol leaves the mouth, it flows down the esophagus and into the stomach. > > Although some absorption, perhaps as much as 20%, takes place in the stomach itself, the overwhelming majority of absorption takes place in the small intestine. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [January 29, 2025, 4:32am UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/7 "2025-01-29T04:32:57Z")
Doc _had_ been standing at the bar, holding the shot, for about 12 hours. Perhaps he was suffering from orthostatic hypotension, and the shot was just enough of a shock to the system to make him faint. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [January 29, 2025, 1:33pm UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/8 "2025-01-29T13:33:42Z")
Case report cites a young woman who passes out after drinking 30 ml of Chardonnay (anaphylactic reaction to alcohol), though it doesn’t mention how rapidly she lost consciousness. > **[Two Case Reports of Life-Threatening Ethanol-Induced Anaphylaxis](https://pmc.ncbi.nlm.nih.gov/articles/PMC2875848/)** > > Adverse reactions to alcoholic beverages are common and diverse in aetiology. Ethanol-induced anaphylaxis, however, is a rare but often life-threatening condition that warrants careful evaluation in suspected individuals. We present the cases of two... Alcohol allergy and anaphylaxis, while rare, exists. ---
**Author:** ![Slithy\_Tove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slithy_tove/32/18248_2.png) [@Slithy\_Tove](https://boards.straightdope.com/u/Slithy_Tove)\ **Post date:** [January 29, 2025, 5:20pm UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/9 "2025-01-29T17:20:52Z")
[Alcohol intolerance](https://en.m.wikipedia.org/wiki/Alcohol_intolerance) is a condition that causes acute nausea. Actor Richard E Grant has it, and suffered an attack when filming Withnal and I when actual booze was used instead of prop tea. Grant, lacking the enzyme to metabolize even one drink, had the same reaction that Anthony Quinn had had when he was at a restaurant awaiting a table with several other actors. Just as the martinis arrived at the bar, their table became available. Quinn, ever frugal, chose to slam six martinis rather than abandon them. He went down like a tree. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [January 29, 2025, 6:03pm UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/10 "2025-01-29T18:03:39Z")
> [@running\_coach](#): > > Alcohol is absorbed all throughout the gastrointestinal tract. Peak blood alcohol concentrations are achieved in as little as 30 minutes or as much as 6 hours. Brings to mind the _Gordon Lightfoot Defence_ ("Sundown, you better take care…"♫) where his lawyer successfully argued that just because he blew over .08 after being arrested when he got to the station does not mean he was over .08 in the car… Needless to say - swiftly overturned on appeal. In the movie, did Doc only have a single shot? How big a glass? ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [January 29, 2025, 6:06pm UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/11 "2025-01-29T18:06:17Z")
People can keel over at the sight of blood. I’m sure there are people that can pass out after the slightest effect of alcohol on their body, or just from believing a drink contains alcohol even if it doesn’t. This probably happens more often than any direct result of consuming an ounce or two of alcohol. There’s also the [Asian Flush reaction that Wikipedia states can occur from 1-60 minutes after consumption of alcohol.](https://en.wikipedia.org/wiki/Alcohol_flush_reaction#Signs_and_symptoms) I assume the 1 minute cases usually involve no more than 1 drink. ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [January 29, 2025, 7:46pm UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/12 "2025-01-29T19:46:54Z")
> [@md-2000](#): > > In the movie, did Doc only have a single shot? How big a glass? Yes, he had only a single shot of whiskey from a shot glass. Couldn’t have been more than 40 ml. ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [January 29, 2025, 8:01pm UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/13 "2025-01-29T20:01:34Z")
> [@TriPolar](#): > > There’s also the [Asian Flush reaction that Wikipedia states can occur from 1-60 minutes after consumption of alcohol.](https://en.wikipedia.org/wiki/Alcohol_flush_reaction#Signs_and_symptoms) I assume the 1 minute cases usually involve no more than 1 drink. That article links to another one on [alcohol-induced respiratory reactions](https://en.wikipedia.org/wiki/Alcohol-induced_respiratory_reactions), which states > Alcohol-induced asthma reactions among Asians has been most thoroughly studied in those of native Japanese descent. In such individuals, the ingestion of virtually any alcoholic beverage or pure ethanol and, in some cases, the smelling of ethanol fumes may be followed, typically within 1–30 minutes, by one or more of the following symptoms: an alcohol flush reaction (i.e. the “Asian flush syndrome”), rapid heart rate, dizziness, light-headedness, urticaria, systemic dermatitis, rhinitis, and, in about half of individuals with a history of asthma, exacerbation of asthmatic bronchoconstriction and related symptoms. In extremely rare instances, asthmatic symptoms in response to alcoholic beverages may occur in the absence of a history of asthma, and cardiovascular collapse, anaphylaxis, and even death may occur. These reactions appear due to a deficiency in the metabolism of the ethanol in the alcoholic beverage. So it seems that certain people can become dizzy and lightheaded, and even lose consciousness (a common effect of anaphylaxis, also mentioned by @Jackmannii), as little as one minute after consuming alcohol. The article notes that such people have a variant allele sometimes found in Asian populations, but I suppose it’s possible that the caucasian Doc Brown had it too as a result of a mutation or remote Asian ancestry. Or more likely, as you point out, it could just be a psychological reaction, which would be in keeping with his high-strung character. ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [January 29, 2025, 8:03pm UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/14 "2025-01-29T20:03:06Z")
> [@TriPolar](#): > > People can keel over at the sight of blood. Jennifer faints at seeing her past self while Jennifer faints at seeing her future self in the second movie. Maybe related to the gravity problems later/earlier in the franchise? Marty is KO’d ‘the easy way…’ ---
**Author:** ![scudsucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scudsucker/32/14101_2.png) [@scudsucker](https://boards.straightdope.com/u/scudsucker)\ **Post date:** [January 29, 2025, 11:46pm UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/15 "2025-01-29T23:46:09Z")
> [@Slithy\_Tove](#): > > Actor Richard E Grant has it, and suffered an attack when filming Withnal and I when actual booze was used instead of prop tea. That is a fact I did not know. It is certainly a cult movie in my Cape Town circle (he is South African) Well known quote from the movie, "[I demand to have some booze"](https://youtu.be/YR1LrPHwo6A?si=C9lAfr1T7czgTxxT) ---
**Author:** ![scudsucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scudsucker/32/14101_2.png) [@scudsucker](https://boards.straightdope.com/u/scudsucker)\ **Post date:** [January 30, 2025, 7:32am UTC](https://boards.straightdope.com/t/can-you-pass-out-from-a-single-drink/1013560/16 "2025-01-30T07:32:33Z")
> [@TriPolar](#): > > People can keel over at the sight of blood. I am one. I also donate blood, so there is an elaborate theatre involving me staring at the ceiling while the nurses cover my arm and the blood bag with paper towels. Not much fun, but the nursing staff handle me extremely well as soon as I tell them of the potential. I also have low alcohol tolerance, but not “1 drink” low. Just enough to get embarrasing before anyone else does, and thus becoming the major topic of gossip at the party.