Sure, that nightcap, last glass of wine or beer before bed might help you feel sleepy. But it can keep you from getting a good night’s sleep, or even worse, cause you to have trouble sleeping.
“Alcohol is a sedative, but both having it in your system and letting it leave your body can cause a variety of problems,” says neurologist and sleep expert Jessica Vensel Rundo, MD. “You’re likely to have trouble sleeping, insomnia, or even more serious problems.
What alcohol really does to the way you sleep
Each night, you go to sleep and wake up at different times. Deep, restful sleep is more likely to happen in the first few hours of sleep and less likely in the second half. As the night goes on, REM sleep comes next, which is when you dream.
If you have a lot of alcohol in your system when you go to bed, you might not sleep very well or for very long. This might happen on and off all night. The sedative effect of alcohol wears off as soon as the body starts to use it.
Dr. Vensel Rundo says that this keeps you from getting the deep sleep and REM sleep you need because the alcohol in your body keeps you in lighter stages of sleep. “You’ll probably wake up more often and more easily, especially as the night goes on.”
Other problems with sleep that alcohol causes
Aside from making you wake up a lot, alcohol can mess up your normal sleep patterns enough to cause problems that you may need to deal with in the long run.
Dreams and nightmares are more likely to be vivid and scary when you’ve had a lot to drink. This is because your sleep patterns will change as you sleep. You might remember them or you might not, but they can be clear or make you feel like you’re half awake and half asleep. Because maybe you will be at some point.
Sleepwalking and parasomnias — You might move around a lot or talk to yourself while you’re sleeping. There’s a chance that you’ll sleepwalk or act out your dreams in real life.
You may also have parasomnias, which are sleep disorders that wake you up or make it hard for you to sleep at certain times. These things can happen when you wake up from REM (rapid eye movement) or NREM (non-rapid eye movement) sleep.
Breathing problems: Because alcohol slows down your whole body, including your muscles, it may make it easier for your airway to close while you sleep. This can make your risk of sleep apnea much higher, especially if you drink in the hours before bed.
How alcohol makes you feel the next day and in the long run
“Like many other drugs, if you drink alcohol before bed, you can expect to feel groggy when you wake up,” says Dr. Vensel Rundo. “Your body will have to make up for the sleep you didn’t get, and you may be less alert as a result.”
When people drink a lot of alcohol for a long time, there can also be long-term problems. Many people who drink too much do it late at night and sleep in the next day. Over time, this could cause you to sleep differently during the day and at night. Then, when the drug or alcohol is taken away, there is a big change in the sleep-wake cycle that needs to be fixed.
“Alcohol also lowers your levels of melatonin, which is the hormone that controls your internal clock,” she says. “If you use drugs or alcohol too much, you could mix up day and night over time.”
What you can do when you can’t sleep
Just cutting down on or giving up alcohol or other drugs can be enough to fix sleep problems (and can greatly improve your health overall).
“But if you keep having trouble sleeping and it doesn’t go away,” says Dr Vensel Rundo, “it’s a good idea to talk to a sleep specialist.”