Night Sweats After Drinking, and When They Mean Withdrawal

It's 4am and the sheets are damp. Your T-shirt is stuck to your back and your pillow is warm. You drank last night, maybe more than you meant to. Sweating is one of the standard hangover symptoms. It can also be an early sign of alcohol withdrawal, which is a different matter and needs a doctor. Here is how to tell the two apart.

Why drinking makes you sweat

Alcohol widens the blood vessels in your skin. In a small study, men who drank a moderate dose of alcohol in a warm room had more blood flowing to their skin and sweated more within ten minutes than when they drank water. They also felt hotter. Their core temperature then dropped, as their bodies shed the heat.

Overnight, that becomes a swing. Sleep researchers have found that alcohol at bedtime first lowers your core body temperature, which then rebounds upward later in the night. Your heart works harder too. In a study of more than 4,000 Finnish employees, heart rate during sleep went up with the amount people drank, and their nervous systems stayed in a more alert, less restful state. The US National Institute on Alcohol Abuse and Alcoholism (NIAAA) lists sweating among the typical hangover symptoms, together with anxiety and raised blood pressure.

The small rebound after every drinking night

Your brain starts adjusting to alcohol within the same evening. NIAAA describes it this way: the brain adapts to alcohol's calming effect, so when the buzz wears off, people can feel more restless and anxious than before they drank. Hangover symptoms peak as the alcohol in your blood falls to about zero, and they can last 24 hours or longer. For the 3am wake-up that often comes with it, see why you wake up at 3am after drinking.

When night sweats can mean withdrawal

If you drink heavily most days, your body may have come to rely on alcohol to stay in balance. Then the overnight drop in alcohol, or a sudden cut in how much you drink, can set off withdrawal. Withdrawal symptoms can begin within 6 to 24 hours of stopping or sharply cutting down, and the NHS says they usually start within 6 to 12 hours of the last drink. If your last drink is at 11pm, that window opens around 5am.

Withdrawal puts the body's fight-or-flight system into overdrive. Doctors look for sweating, a fast heart rate, tremor, raised blood pressure, anxiety and agitation among its first signs. That is why withdrawal sweats tend to arrive with a pounding heart and shaky hands.

Signs that the sweats may be withdrawal rather than an ordinary hangover:

• They come with shaky hands, anxiety as soon as you wake, or nausea or retching in the morning. The NHS lists these as mild to moderate withdrawal symptoms that suggest you may need medicine to stop drinking safely.
• They show up after nights when you drank less than usual, or nothing at all.
• They come back most nights, along with trouble sleeping and a racing heart as the alcohol wears off.

NIAAA counts withdrawal symptoms like these among the signs of alcohol use disorder. It's a medical condition, and doctors can prescribe medicine that makes withdrawal safer and less distressing. Our short drinking self-check can help you see where you stand before you talk to someone.

Urgent signs

Severe withdrawal can be life-threatening. Seek urgent care, or call your local emergency number, if sweating comes with any of these:

• severe shaking you can't control
• confusion, such as not knowing what day it is
• seeing or hearing things that aren't there
• a seizure
• a racing heart with heavy sweating

The most severe form of withdrawal, delirium tremens, can start days after the last drink, anywhere from about day three to day eight. A quiet first day or two doesn't mean you're in the clear.

If you drink heavily every day, stopping suddenly can be dangerous. Talk to a doctor first. NIAAA notes that withdrawal can be life-threatening when people who drink heavily stop suddenly, and that cutting back gradually or stopping with medical support is the safer route. Our guide on when to see a doctor about drinking covers what that conversation looks like.

Other causes worth knowing

Drinking is one of several common causes of night sweats. The NHS also lists menopause, anxiety, low blood sugar, and medicines such as some antidepressants, steroids and painkillers. If you have diabetes, drinking a lot of alcohol, especially without eating, can cause low blood sugar, and sweating and shaking are among its symptoms. If you're going through the menopause, the NHS suggests cutting down on alcohol as one way to reduce triggers for hot flushes and sweats. Anxiety is on the list in its own right, and it is also part of both hangovers and withdrawal, so the causes can overlap.

See a GP if you have night sweats regularly that wake you up or worry you, if you also have a very high temperature, a cough or diarrhea, or if you're losing weight for no reason.

What helps

For an ordinary hangover sweat, keep the bedroom cool and keep water by the bed. The bigger lever is the amount: in the Finnish study, the heart-rate effects rose step by step with how much people drank. The NHS advises no alcohol in the 6 hours before bed, which gives your body longer to clear it before you sleep.

It also helps to keep a simple record. Note the nights you wake up sweating next to what you drank the evening before. Sweats that only follow your heaviest nights look like the hangover kind. Sweats on nights when you drank less, or with shaking and a racing heart, are the ones to take to a doctor.

If the sweats are part of a daily pattern, the useful next step is a conversation with a doctor before you change anything sharply. Cutting down is still possible, and a doctor can help you do it safely.