Why Am I So Thirsty at Night? Causes and Solutions

It’s tough to tell exactly what causes excessive thirst at night, but there are some possibilities to consider. While most are benign and easily fixable, others are a little more serious and may require a trip to the doctor to see what’s up.

If you and your emotional support water bottle have been attached at the “sip” lately, especially as you’re lying in bed at night, this one’s for you. Learn about possible causes here, plus how to quench that thirst.

7 reasons why you’re so thirsty at night

Your thirst signal is a good thing, and often means it’s time to start drinking as soon as that ding-ding-ding goes off in your brain. But sometimes, excessive thirst can tell you something in your body’s off. Here’s what could be going on.

1. You’re dehydrated

If your days have been particularly busy lately, you may be forgetting to sip water. Once you finally get a chance to slow down (i.e., when you’re in bed at the end of the day), you may realize how thirsty you are. It’s possible that you’re dehydrated, which comes with a host of other symptoms, like dry mouth, dark-colored urine, and fatigue, according to the National Library of Medicine. You can remedy this by making sure you get plenty of water and H2O-rich foods throughout the day—like fruits, veggies, yogurt, and other beverages like tea.

2. It’s your medication

Certain medications may make you pee more. Diuretics, which may be prescribed to treat high blood pressure, are one classic example, says Orlando Ruiz-Rodriguez, MD, a pulmonologist and sleep medicine specialist with Orlando Health Medical Group Pulmonology and Sleep Medicine. Also called water pills, diuretics encourage your kidneys to release more water and sodium in your urine. You pee more, which can increase the risk for dehydration—and that could turn up your thirst.

3. You’re breathing through your mouth

Unless you share a bed, it’s hard to know how you’re breathing when you’re fully asleep. One clue that you’re sleeping with your mouth wide open? It feels really dry and cotton-y when you wake up. “We lose a lot of moisture in our breathing during the night,” says Christopher Winter, MD, a sleep medicine specialist and author of The Sleep Solution.

“Even if you don’t snore, you lose more moisture when breathing through your mouth compared to breathing through your nose. It’s awful to wake up with a dry mouth where your tongue feels like leather,” he says. Mouth breathing may happen for a host of reasons, including nasal congestion, snoring, or a sleep condition like sleep apnea. (More on this below.)

4. You have sleep apnea

There are many reasons why someone might snore or breathe through their mouth during sleep—one being sleep apnea. It’s a condition where a person stops breathing for short pauses throughout the night. This can affect your sense of thirst in a couple of ways. “People with sleep apnea tend to open their mouths to clear their airways. That exposure to air may dry out the oral mucosa,” says Dr. Ruiz-Rodriguez.

Sleep apnea episodes may also engage your sympathetic nervous system—aka, your fight, flight, or freeze response—which can cause you to wake up feeling like you have to pee throughout the night. In fact, urination habits are a major clue for diagnosing sleep apnea.

“If you’re peeing more at night than during the day, the problem may be sleep related,” he says. Getting up to pee may also lend itself to taking a swig of water before returning to the sack.

5. You’re drinking alcohol

Feeling thirsty after a night of drinking is pretty common. Why’s that? Alcohol is a diuretic—i.e., it makes you pee more. This means, with every cocktail or glass of wine you drink, your body is losing fluid, Dr. Winter says. Reaching for your water bottle may not only help curb the inevitable hangover, but it will also quench your excessive thirst.

What’s more, binge drinking (or chronically heavy alcohol use) increases your urge to drink water by acting on your central nervous system—which causes dry mouth and a bump in thirst sensations, per a small August 2017 review in Japanese Dental Science Review. Even light-to-moderate amounts of alcohol can mess with your sleep by increasing your risk of snoring (and dry mouth), per a March 2024 study in Molecular Psychiatry.

6. Your environment is hot and humid

Sleeping in a room that’s hot and stuffy can also increase thirst at night. “Humidity can make you uncomfortable and sweaty,” says Dr. Winter. And as you sweat, you lose fluids—meaning it’s possible an overheated room can make you thirsty, too. This is especially troublesome for people going through perimenopause or menopause night sweats (i.e., hot flashes that happen at night), which can leave you drenched in sweat.

Keeping your room cool and dry can help tamp down your thirst levels in the p.m.

7. You have an underlying health problem

Excessive thirst at night (or any time of the day, really) could indicate an underlying health condition. For example, people with unmanaged diabetes may experience increased thirst and therefore drink more water, per the Mayo Clinic. They may also have to pee two or more times per night—a condition called nocturia.

Other conditions that can cause excessive nighttime thirst and nocturia include the following, per the Urology Care Foundation:

• Diabetes
• High blood pressure
• Heart disease
• Overactive bladder
• Menopause
• Restless leg syndrome

How to get rid of excessive thirst at night

Excessive thirst before bed (or in the middle of the night) can be disruptive to your sleep. Here’s what you can do to tone down the urge to overindulge—in water, that is:

Drink water during the day

Ideally, you’ll want to get anywhere from 11.5 to 15.5 cups of water per day through drinking and eating water-rich foods, per the National Academies of Sciences, Medicine, and Engineering. While you can use this as a framework to help keep you on track, you can also just sip water throughout the day—with meals, when you exercise, or whenever you feel thirsty, per the Mayo Clinic.

That way, once you approach bedtime, you won’t feel compelled to chug before you sleep.

Think about your room temp and humidity

If your room is dry, hot, and humid at night, it’s time to make some changes. Some things that may help?

• Install a ceiling fan if you can
• Run a humidifier in the winter (to make your room less dry)
• Run a dehumidifier in the summer (to make things less humid and sticky)

Just keep in mind: You may still feel thirsty after all is said and done. “I don’t know if those things would affect your thirst, but they may be worth a try,” says Dr. Winter. Regardless, making your room environment more comfortable will help your sleep quality, too.

Watch what you wear

Wearing looser pajamas can help keep you cool, says Dr. Winter. You can even try using a cooling pillow or mattress to minimize sweating. Whatever you choose, cutting down on the amount you sweat in your sleep could lower your thirst levels, too.

Ask about your medications

If you think a medication could be the culprit behind your thirst at night, talk to your doctor. Excessive thirst (and even nighttime urination) could be a possible side effect. Your doctor might be able to prescribe something else, adjust your dose, or recommend you take it at a different time of day to decrease nighttime thirst.

Just be sure to check in with your doctor before making any changes.

Avoid alcohol before bed

According to an April 2024 study in Sleep, having even one alcoholic drink before bed is associated with slumber-disrupting effects. If you want to reduce your chances of thirst and poor sleep, stop drinking alcohol a couple hours before bed. And keep your average daily intake low—about one to two drinks per day (or less, if possible), according to the Centers for Disease Control and Prevention.

Talk to your doctor about your sleep

Drinking water may feel good in the moment for constant dry mouth, but getting to the root cause (like an underlying sleep disorder) is even more helpful. Talk to your doctor about the possibility of sleep apnea. They can refer you for a sleep study, or test you for other conditions that lead to thirst, nighttime urination, and poor sleep—like diabetes, kidney disease, or prostate problems.

When to see a doctor about excessive thirst at night

Feeling thirsty before bed every once in a while is normal. Maybe you forgot to drink enough water throughout the day, or the air in your bedroom is particularly stuffy, which can both be fixed relatively easily.

But if your sense of thirst is extreme, sudden, or comes with other symptoms like urinary issues or fatigue, it’s time to make an appointment with your doctor. They may want to order a sleep study to rule out things like sleep apnea, or get your blood tested to make sure you don’t have an underlying condition like diabetes.