Alcohol’s Impact on the Body and Brain 

Mar 28, 2024


Alcohol can make you sick. And not just a hangover.  

It’s National Alcohol and Drug Facts Week. Here’s one now: Alcohol can cause problems even in people who do not have a substance use disorder.  

Did you know one night of heavy drinking weakens your immune system for up to 24 hours? You’re vulnerable to whatever viruses or bacteria are floating around out there.  

Hangovers aren’t so harmless, either. Think of them as mini-withdrawals. Along with the physical discomfort, the brain still reels all the next day, affecting balance, mood, decisions and more.   

Speaking of decisions, lots of risky ones get made under the influence: driving, shopping, gambling, sex, taking dares, all of which can have life-changing consequences beyond a night of casual drinking.  

If drinking is more than casual, that’s a whole different level of risk. Alcohol is a carcinogen, just like nicotine. We’re talking cancer of the breast, colon, oral cavity and rectum. The liver, which processes alcohol, takes a big hit.   

What’s “a lot” of drinking?  

Binge drinking is five or more drinks (male), or four or more drinks (female), in about two hours.  

Heavy drinking is defined for men as five or more drinks on any day, or 15 or more per week. For women, it’s four or more on any day, or eight or more drinks per week  

What’s “moderate” drinking?  

U.S. dietary guidelines say “moderation” is about 1-2 drinks a day for men and one or fewer drinks daily for women.  

What’s a “drink”?  

The National Institutes of Health defines one drink as:  

  • 12 ounces of regular beer, about 5 percent alcohol  
  • 5 ounces of wine, about 12 percent alcohol   
  • 1.5 ounces of distilled spirits, about 40 percent alcohol (80 proof)  

But it’s easy to drink a lot more than we realize or intend. Many craft beers and ales are far higher in alcohol. Drinking a 15-percent alcohol beer is actually three drinks in one bottle.   

Two servings of port wine or liqueur amount to three or four drinks.  

Hard liquor of 120 or 150 proof is several drinks in one.  

Cocktails mixed in a bar are a mystery – there’s no way to know how many “drinks” are in that glass.  

Humans have been consuming alcohol for thousands of years. Most do not develop substance use disorder, though that doesn’t mean there can’t be consequences from occasional bouts of heavy drinking (see: risky decisions).  

Awareness is the key to moderation and limiting alcohol’s risks to our health and life.   

Learn more  

Lifeworks NW: When does drinking cross the line into disorder? Check out symptoms  

National Institute of Alcohol Abuse and Alcoholism: Alcohol’s effects on health