A night out can quickly become less fun if you feel like you’re in the bathroom peeing the whole time.

Alcohol is a diuretic. Drinking it can make you pee more than if you had the same amount of water.

Read on to find out the science behind why alcohol makes you pee — and what, if anything, you can do to keep from having to constantly go to the bathroom.

There are a few factors at play for why you can feel the need to pee more when you drink alcohol versus when you drink the same amount of water.

Alcohol is liquid and your kidneys know it

First, your kidneys regulate the amount of water in your body. They do this by monitoring the plasma osmolality of your blood.

Osmolality is a fancy word to describe the ratio of particles in your blood to fluid. If you have more fluid than particles, your kidneys tell your body to release more urine.

When you have more particles than fluid, your kidneys hold on to fluid, and you don’t feel the need to pee.

Because alcohol is a liquid, it tips the osmolality in favor of more fluid. As a result, you’ll ultimately pee out the equivalent of what you drink (assuming your kidneys are working well).

Summary

Your kidneys keep track of the balance of particles to fluid in your blood. When fluid levels go above a certain amount, you’ll ultimately pee.

Alcohol is a diuretic

The second factor that makes alcohol more likely to make you pee is that it’s a diuretic. But what does that mean, exactly?

Drinking alcohol inhibits the body’s release of the hormone vasopressin. Doctors also call vasopressin anti-diuretic hormone (ADH).

Typically, the brain signals the release of ADH in response to an increase in particles over fluids (plasma osmolality). The ADH signals your kidneys to hold on to water.

By suppressing ADH, alcohol can make the kidneys release more water. This can have a dehydrating effect on your body that not only makes you pee more, but can also cause headaches and nausea later.

Summary

Alcohol inhibits your body’s release of a hormone that helps your kidneys function correctly. As a result, your kidneys and body may feel the need to release more liquid than they need to. This can also make you dehydrated.

Here are a few factors that can affect how much you pee when you drink alcohol.

Alcohol strength

According to a study in the journal Alcohol and Alcoholism, a person’s urine output increased when alcohol content went up from 2 percent to 4 percent compared to an alcohol-free drink.

Another study published in the journal Nutrients found drinking moderate amounts of higher-alcohol beverages, such as wine and distilled liquors, provoked a small diuretic effect. By comparison, they found lower-alcohol beverages, like beer, didn’t have as much of a diuretic effect.

How often you drink

Your body seems to become accustomed to the presence of alcohol when it comes to peeing. Therefore, the more frequently a person drinks, the less diuretic effects alcohol is likely to have.

This isn’t a reason to drink more, though! Just an example of how the body regulates itself.

Hydration levels before drinking

The same study in Alcohol and Alcoholism reported that people who were slightly underhydrated before drinking alcohol urinated less than those who were hydrated, even when drinking the same amount of alcohol.

However, most research suggests people’s bodies still respond differently to alcohol. Some people may find they pee more when they drink it, while others pee less.

“Breaking the seal” is a term used for the first time a person pees when they’re drinking alcohol.

Some people believe when a person breaks the seal, it makes them pee more frequently. As a result, they try to hold out on peeing until they absolutely have to go.

There’s no research to support the idea that breaking the seal is a real thing. Instead, doctors propose the theory may be more of a mental suggestion to a person when drinking.

If you think breaking the seal makes you pee more, you’ll probably start thinking about going to the bathroom more, and therefore pee more frequently.

Generally, it’s not a good idea to resist the urge to urinate when you feel like you need to go. Holding it in repeatedly can increase your risk for urinary tract infections (UTIs) and affect your bladder-brain connection that signals when you need to pee.

Maybe you’ve heard a story from a friend (or maybe you’re that friend) who went through a full night of drinking and woke up having peed on themselves. This can likely signal what you already know: They drank too much.

Why did it happen?

Drinking to excess can cause you to fall asleep more easily or even to “black out.” When this happens, you don’t wake up like you usually might when your bladder signals your brain that you need to pee.

But your bladder is still filling up due to the alcohol you drank. And there’s a critical mass when your bladder fills up so much that it becomes distended. You ultimately pee whether you want to or not.

Can I avoid it?

The solution here is to drink in moderation. Go to the bathroom before you go to sleep so your bladder is as empty as possible.

What’s a ‘moderate’ amount of alcohol?

Moderation is one drink for women and one to two drinks for men per day. According to the National Institute on Alcohol Abuse and Alcoholism, the following are the equivalents of one drink:

  • 1.5 ounces of distilled spirits, such as rum, tequila, or vodka
  • 5 ounces of wine
  • 12 ounces of a beer that’s about 5 percent alcohol

Like many factors related to portion sizes, you might be served a larger pour at many bars and restaurants.

Keeping in mind the factors that influence alcohol and having to pee, here are the most common ways you can manage the need to pee:

  • Do drink beverages with a lower total alcohol content. For example, drink a glass of wine instead of a cocktail with hard liquor.
  • Don’t keep yourself slightly dehydrated to pee less. It isn’t a great plan overall since dehydration will probably only make you feel worse later.
  • Do drink in moderation. If you don’t fill your body and bladder up with as much alcohol, you won’t have to pee as much.

Alcohol does make you pee more by affecting hormones in your body. Limiting your alcohol intake to one to two drinks during an evening out can help cut down on your bathroom trips — and reduce the likelihood you could have an overnight accident.