How sleep affects a hangover

A good time can quickly turn into a bad day when poor quality sleep follows a night of drinking. A Baylor College of Medicine toxicologist explains how alcohol interferes with the sleep cycle, exacerbating the effects of a hangover.

“Alcohol is effective with sleep initiation, so there is a perception of it being a sleep aid,” said Dr. Sarah Shafer, assistant professor of emergency medicine at Baylor. “While it helps you get to sleep a little more quickly, it interferes with sleep, which will contribute to the feelings of a hangover because you’re not only dealing with the effects of alcohol, but you’re also dealing with the effects of interrupted sleep and worse-quality sleep.”

After drinking, the brain compensates during sleep, leading to poor quality sleep. You spend less time in REM and are prone to waking up, even if you fail to remember it. While it is unknown why the brain changes its rhythms in response to alcohol, one theory is that alcohol causes shifts in the rest of the sleep cycle. A shorter night of sleep will contribute to a worse hangover, concentration effects and worse cognitive performance.

“Sleep has multiple cycles and rhythms, so what we often think of as one concrete thing actually has a lot of variations within it that can be affected,” Shafer said.

If you feel hungover and your body feels tired from the effects of alcohol, you may consider a daytime nap to compensate for the sleep deprivation from the night before. But be careful because napping during the day may cause long-term problems since it can further interrupt sleep later that evening, which can lead to a compounding effect. People who drink alcohol multiple nights in a row or drink more regularly will experience chronic sleep interruption from the quality of sleep and constant napping. Alcoholics have chronic sleep problems because of their chronic alcohol use. When they stop drinking, their sleep problems persist because chronic alcohol use can lead to long-term sleeping issues.

While enjoying a night of drinking occasionally will not cause problems, it is important to understand how alcohol can affect sleep and cause poor quality sleep. Shafer suggests moderate consumption to ensure a good night of rest.

“Our cultural understanding of alcohol as a sleep aid is not accurate and using alcohol to sleep can hurt you in the long run,” she said.

Shafer suggests how to lessen the effects of a hangover:

• Stay hydrated
• Try to get a good night’s rest
• Avoid multiple episodes of drinking in a short period of time
• Avoid the “hair of the dog”: more alcohol the next day may temporarily make you feel better, but it will eventually contribute to a worse hangover

“Having healthy habits around drinking alcohol and being thoughtful about alcohol use is going to be the best way to limit the hangover effects,” Shafer said.

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By Homa Shalchi