# Alcohol and dehydration **URL:** \ **Category:** Factual Questions\ **Created:** [June 17, 2019, 12:51pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639 "2019-06-17T12:51:22Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Vic\_Parrish](https://avatars.discourse-cdn.com/v4/letter/v/c6cbf5/32.png) [@Vic\_Parrish](https://boards.straightdope.com/u/Vic_Parrish)\ **Post date:** [June 17, 2019, 12:51pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/1 "2019-06-17T12:51:22Z")
I’ve heard all my life that alcohol causes dehydration. I have also heard that people in the Middle Ages often drank beer or cider because it was less likely to carry bacteria than the local water supply. I have also noticed that after drinking a moderate amount of beer (really!) my urine is almost colorless, a sign that I am NOT dehydrated. What’s the deal? This seems contradictory to me. Is it a matter of ABV or proof? I’m sure the sages on this site can set things straight for me. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [June 17, 2019, 1:00pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/2 "2019-06-17T13:00:00Z")
> [@Alcohol and dehydration](https://boards.straightdope.com/t/alcohol-and-dehydration/835638/1): > > I I have also noticed that after drinking a moderate amount of beer (really!) my urine is almost colorless, a sign that I am NOT dehydrated. I don’t think this is true. Your pee is clear because alcohol is a diuretic. > [@](#): > > “Alcohol is a diuretic,” says Professor Oliver James, Head of Clinical Medical Sciences at Newcastle University. “It acts on the kidneys to make you pee out much more than you take in – which is why you need to go to the toilet so often when you drink.” In fact for every 1g of alcohol drunk, urine excretion increases by 10ml1. > > Alcohol also reduces the production of a hormone called vasopressin, which tells your kidneys to reabsorb water rather than flush it out through the bladder. With the body’s natural signal switched off, the bladder is free to fill up with fluid. > **[Why does alcohol make you pee more? | Drinkaware](https://www.drinkaware.co.uk/facts/health-effects-of-alcohol/general-health-effects/why-does-alcohol-make-you-pee-more)** > > Find out why exactly drinking alcohol make us need to pee more than when we drink soft drinks or water? ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [June 17, 2019, 1:12pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/3 "2019-06-17T13:12:39Z")
Duplicate post, reported ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [June 17, 2019, 1:22pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/4 "2019-06-17T13:22:39Z")
A couple issues: – If it does dehydrate you, your urine will be clear _until you’re dehydrated_. Your urine will not be dark when you’re in the middle of _getting_ dehydrated but not dehydrated yet. – Part of it is indeed the alcohol percentage. I’m not sure if beer and cider will dehydrate you in an absolute sense or just simply not hydrate you as much as water, but I’m pretty sure hard liquor will have a worse effect than beer and would, at least initially, dehydrate you. Not sure if the body would eventually compensate for this if you were a hard core boozer. ---
**Author:** ![Vic\_Parrish](https://avatars.discourse-cdn.com/v4/letter/v/c6cbf5/32.png) [@Vic\_Parrish](https://boards.straightdope.com/u/Vic_Parrish)\ **Post date:** [June 17, 2019, 1:25pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/5 "2019-06-17T13:25:47Z")
> [@kayaker](#): > > Duplicate post, reported Thanks. A little too eager with it. Perhaps a nice cider would calm me down. ---
**Author:** ![Vic\_Parrish](https://avatars.discourse-cdn.com/v4/letter/v/c6cbf5/32.png) [@Vic\_Parrish](https://boards.straightdope.com/u/Vic_Parrish)\ **Post date:** [June 17, 2019, 1:27pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/6 "2019-06-17T13:27:02Z")
> [@Ludovic](#): > > A couple issues: > > ## – If it does dehydrate you, your urine will be clear _until you’re dehydrated_. Your urine will not be dark when you’re in the middle of _getting_ dehydrated but not dehydrated yet. This is generally after I have dark urine BEFORE I begin the consumption. I am a former safety manager, so I notice this sort of thing. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 17, 2019, 1:34pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/7 "2019-06-17T13:34:45Z")
Alcohol dehydrates you. Water hydrates you. Beer (or in fact, any alcoholic beverage) contains both alcohol and water. So the net effect depends on the relative amount of alcohol and water. It’ll vary some from person to person, but typically, it’ll be on net more hydrating than dehydrating until you get to strong distilled stuff. As for the urine: There’s some amount of waste products that your body needs to get rid of. That’s what gives urine its color. Alcohol doesn’t change that. And there’s also some amount of water that goes with that. Alcohol does change the amount of water. The way that alcohol dehydrates you is by making your body excrete more water. Excreting a lot of water means that your urine is clear. By contrast, when you’re not under the influence of any drug that affects your kidneys, the reason that you’d be excreting a lot of water would be that your body has more water than it needs. That’s why, in that case, clear urine is a sign of adequate hydration. ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [June 17, 2019, 1:36pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/8 "2019-06-17T13:36:21Z")
I’m not sure it’s a clearly detailed as we think, but this article [Hydration and health: a review](https://onlinelibrary.wiley.com/doi/full/10.1111/j.1467-3010.2009.01795.x) cited in [The Diuretic Action of Weak and Strong Alcoholic Beverages in Elderly Men: A Randomized Diet-Controlled Crossover Trial](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537780/#B15-nutrients-09-00660) has an interesting graph with water loss/gain vs various beverages - Beer is a gain, wine and spirits a loss > [@](#): > > Alcoholic beverages vary in their water and alcohol content, with a standard measure of beer containing much more water than a standard measure of spirits. Alcohol has a diuretic effect, and so the effect of consuming alcoholic beverages on overall water balance depends on the amount of alcohol vs. the water consumed. Consumption of strong alcoholic drinks without additional fluids can cause dehydration (James & Ralph 2001). ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [June 17, 2019, 1:38pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/9 "2019-06-17T13:38:03Z")
**Moderator Note** > [@kayaker](#): > > Duplicate post, reported The duplicate threads have been merged. ---
**Author:** ![Fretful\_Porpentine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fretful_porpentine/32/2873_2.png) [@Fretful\_Porpentine](https://boards.straightdope.com/u/Fretful_Porpentine)\ **Post date:** [June 17, 2019, 1:41pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/10 "2019-06-17T13:41:28Z")
Two things: First of all, a lot of medieval beer, particularly that drunk by ordinary working folks, was [small beer](https://en.wikipedia.org/wiki/Small_beer), which is very low-alcohol, and probably would keep you acceptably hydrated. Secondly, the “medieval people didn’t drink water because it was unsafe” thing [appears to be largely a myth](http://www.medievalists.net/2014/07/people-drink-water-middle-ages/). In most cases, people probably were drinking water as well as beer on a regular basis, they just didn’t tend to leave written records about it any more than we do. ---
**Author:** ![Vic\_Parrish](https://avatars.discourse-cdn.com/v4/letter/v/c6cbf5/32.png) [@Vic\_Parrish](https://boards.straightdope.com/u/Vic_Parrish)\ **Post date:** [June 17, 2019, 1:42pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/11 "2019-06-17T13:42:11Z")
> [@Grey](#): > > Beer is a gain, wine and spirits a loss With nothing more scientific than my untested perception, this is the closest to my experience. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [June 17, 2019, 1:48pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/12 "2019-06-17T13:48:04Z")
> [@Vic\_Parrish](#): > > This is generally after I have dark urine BEFORE I begin the consumption. I am a former safety manager, so I notice this sort of thing. I am not a doctor, but I would think a diuretic would cause your kidney to produce more urine (i.e. converting more water from your blood into urine) and make it a lighter color. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [June 17, 2019, 2:33pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/13 "2019-06-17T14:33:19Z")
> [@Chronos](#): > > Excreting a lot of water means that your urine is clear. That’s maybe a bit oversimplified. Bilirubin can make the urine a dark yellow color. Bilirubin, a breakdown product of red blood cells, is normally handled by the liver and excreted in the bile. The liver can be overwhelmed by large amounts of bilirubin and the excess will be excreted by the kidneys, leading to yellow urine even if the person is well hydrated. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [June 17, 2019, 3:05pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/14 "2019-06-17T15:05:50Z")
> [@Vic\_Parrish](#): > > I’ve heard all my life that alcohol causes dehydration. I have also heard that people in the Middle Ages often drank beer or cider because it was less likely to carry bacteria than the local water supply. I have also noticed that after drinking a moderate amount of beer (really!) my urine is almost colorless, a sign that I am NOT dehydrated. What’s the deal? This seems contradictory to me. Is it a matter of ABV or proof? I’m sure the sages on this site can set things straight for me. Well, it’s true and not true. You can live fine (if your liver can stand it) with wine or beer as your primary water intake. The small amount of alcohol wont really effect your hydration. Same with caffeine, like coffee. In fact I knew of some fishermen that drank nothing but black coffee and red wine for a couple of days. But if you’re doing tequila shots and not getting any other substancial form of hydration, yes, you could be in trouble. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [June 17, 2019, 3:08pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/15 "2019-06-17T15:08:35Z")
> [@Chronos](#): > > Alcohol dehydrates you. Water hydrates you. Beer (or in fact, any alcoholic beverage) contains both alcohol and water. So the net effect depends on the relative amount of alcohol and water. > > It’ll vary some from person to person, but typically, it’ll be on net more hydrating than dehydrating until you get to strong distilled stuff. > … Right. Water with some small amounts of sodium, potassium, and a couple other trace minerals is the best. But beer or wine will keep you hydrated. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [June 18, 2019, 4:27am UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/16 "2019-06-18T04:27:51Z")
> [@DrDeth](#): > > Well, it’s true and not true. You can live fine (if your liver can stand it) with wine or beer as your primary water intake. The small amount of alcohol wont really effect your hydration. Same with caffeine, like coffee. In fact I knew of some fishermen that drank nothing but black coffee and red wine for a couple of days. > > But if you’re doing tequila shots and not getting any other substancial form of hydration, yes, you could be in trouble. See Post 8 and the cite referenced. Beer is fine, wine is not. ---
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [June 18, 2019, 3:55pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/17 "2019-06-18T15:55:58Z")
I dunno. The day after a night of heavy beer drinking I can drink a lot (water, more beer, whatever) before I have to pee for the first time. I assume that’s because I’m dehydrated because, at some point and for reasons quoted by Fear Itself, I’ve pee’d out more than I’ve taken in. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [June 18, 2019, 6:04pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/18 "2019-06-18T18:04:21Z")
> [@TokyoBayer](#): > > See Post 8 and the cite referenced. Beer is fine, wine is not. Wine is only 11% or so, only twice beer. Now some fortified wines are quite high, and in fact some few beers are also. Of course YMMV. From that cite “In conclusion, only moderate amounts of stronger alcoholic beverages (≥13.5%) resulted in a temporary diuretic effect compared to their non-alcoholic counterparts”. However, with wine you are getting close. Beer is OK, except the very high alcohol content ones. ---
**Author:** ![Esprise\_Me](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/esprise_me/32/2947_2.png) [@Esprise\_Me](https://boards.straightdope.com/u/Esprise_Me)\ **Post date:** [June 18, 2019, 7:11pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/19 "2019-06-18T19:11:57Z")
> [@DrDeth](#): > > Wine is only 11% or so, only twice beer. Now some fortified wines are quite high, and in fact some few beers are also. Of course YMMV. French wine, yes. California wines are often more like 14-16%. Warmer climates can result in higher sugar levels in the grapes which can turn into more alcohol. Market forces also have an effect; we Americans apparently like sweet strong wine. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [June 18, 2019, 7:14pm UTC](https://boards.straightdope.com/t/alcohol-and-dehydration/835639/20 "2019-06-18T19:14:44Z")
> [@Esprise\_Me](#): > > French wine, yes. California wines are often more like 14-16%. Warmer climates can result in higher sugar levels in the grapes which can turn into more alcohol. Market forces also have an effect; we Americans apparently like sweet strong wine. Sure. But not sweet, the wine I see is highly tannic and not allowed to age. And I suppose it’s not a sharp cut off either. So- Most beers are Ok Wine is a maybe. Hard booze is a no. [Next page](https://boards.straightdope.com/t/alcohol-and-dehydration/835639.md?page=2)