Why is my tongue white after drinking alcohol?

Cleveland Clinic lists drinking more than one alcoholic drink a day as a cause of white tongue, explaining that it can lead to dehydration. The NHS lists heavy alcohol use as a cause of dehydration and advises avoiding alcohol when your mouth is dry. Mayo Clinic also names alcohol use among the common causes of a white tongue.

A night of drinking stacks several drying effects together:

• Alcohol increases fluid loss, so you start the night dehydrated.
• Saliva naturally falls during sleep.
• Many people snore or breathe through their mouth after drinking, which dries the tongue surface further.
• Late-night food, sugary mixers and skipped brushing leave more debris behind.

The result is the classic morning-after tongue: white or yellowish, furry and often paired with bad breath.

1. Drink water steadily through the morning. If you feel sick, start with small sips.
2. Brush your teeth and clean your tongue gently from back to front. Most of the film should lift easily.
3. Eat something with some texture when you can; chewing stimulates saliva.
4. Skip alcohol-based mouthwash. The NHS suggests alcohol-free mouthwash for a dry mouth, because alcohol can make dryness worse.
5. Go light on coffee until you have rehydrated.

If you drink regularly, a glass of water between drinks and one before bed helps prevent the coating in the first place.

The National Cancer Institute explains that alcohol is a known cause of cancers of the mouth, throat and voice box. Compared with not drinking, heavy drinking makes mouth and throat cancer about five times as likely, and the risk is much greater in people who both drink and smoke, because the two multiply each other's effects. Stopping drinking is associated with a lower risk over time.

The NHS lists drinking more than the recommended amount of alcohol as a risk factor for leukoplakia, a white patch that cannot be scraped away and carries a small risk of becoming cancer. Cleveland Clinic links leukoplakia to alcohol and tobacco use.

None of this means a hangover tongue is dangerous. It means that if you drink heavily, any white patch that does not clean off, or any mouth sore that lasts more than about 3 weeks, should be checked rather than ignored.

Book a dental or medical appointment if the white tongue does not clear after a few days without alcohol and with daily cleaning, if there is a patch you cannot remove, or if your mouth is sore. Tell them honestly how much you drink, because it changes what they look for. If you want to cut down, your doctor can help with that too.