Why BAC Can Keep Rising After a Person Stops Drinking

BAC – blood alcohol content or concentration – refers to the amount of alcohol in the bloodstream.


When a person drinks more than their liver can metabolize (process), their BAC can keep rising long after they’ve stopped drinking.

Why BAC Can Keep Rising After a Person Stops Drinking

Alcohol enters the bloodstream through the walls of the small intestine. Because alcohol dissolves in water, the bloodstream carries it throughout the body (which is 60-70%) water, where it is absorbed into body tissue high in water concentration (like the brain) and highly vascularized (meaning, lots of blood vessels – like the brain).

Alcohol is metabolized by the liver, thanks in large part to enzymes produced in the liver. This is the process by which alcohol leaves the body. The liver can only metabolize a certain amount of alcohol per hour, which means alcohol leaves the bloodstream more slowly than it enters. [This is why a person’s BAC can continue to rise after they have stopped drinking.] Because the brain controls everything we think, feel, say and do, alcohol “sitting” in the brain until the liver can metabolize it changes a person’s “thinking” and therefore their behaviors.

A very GENERAL rule of thumb is that it takes about one hour for the liver to metabolize one standard drink. A standard drink is defined as 5 ounces of table wine, 12 ounces of beer or 1.5 ounces of hard liquor. Using this very GENERAL rule of thumb, it will take two hours to metabolize two drinks — even if the drinks were consumed back-to-back, and it’s been over an hour.

BUT, no two people will necessarily metabolize alcohol in the same manner. People who weigh less, for example,  have less body water as compared to someone who weighs more, and thus drink for drink a person who weighs less will have more alcohol concentration in their body water than someone who weighs more. People who have lower amounts of the liver enzymes that metabolize alcohol will take longer to metabolize the same amount of alcohol as someone else. Stage of brain development also has an influence. [See related post for more on this concept, “Underage Drinking – How Teens Become Alcoholics Before Age 21“. There are other factors that can also influence how much is “too much” for one person as compared to another.

The key message is the liver can only metabolize a certain amount of alcohol per hour. Until the alcohol is metabolized, a person still has alcohol in their bloodstream, which means their brain is still being impacted by the alcohol in their bloodstream – hence their decision-making capabilities are being impacted, as well. In this manner, a person who’s had too much to drink may actually “choose” to drink and drive or to keep drinking because “they feel fine” or engage in any number of other destructive behaviors because of the convoluted “thinking” caused by alcohol’s impact on their brain.

Revised 12.11.11

Lisa Frederiksen

Lisa Frederiksen

Author | Speaker | Consultant | Founder at BreakingTheCycles.com
Lisa is the author of hundreds of articles and 11 books, including "If You Loved Me, You'd Stop!," "Addiction Recovery: What Helps, What Doesn't," and "Secondhand Drinking: the Phenomenon That Affects Millions." She is a national keynote speaker with over 25 years speaking experience, consultant, and founder of BreakingTheCycles.com. She has spent more than 14 years studying 21st century brain research in order to write, speak, and consult on substance use disorders prevention, intervention and treatment; mental disorders; addiction (aka substance use disorders) as a brain disease; adolescent addiction treatment vs adult addiction treatment; effective treatment for co-occurring disorders (having both a substance use and mental disorder); secondhand drinking | drugging; help for the family; and related subjects. In 2015, she founded SHD Prevention, providing training and consulting to companies, public agencies, unions, nonprofits and other entities to address the workplace impacts of employee secondhand drinking and alcohol misuse.
Lisa Frederiksen

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3 Responses to Why BAC Can Keep Rising After a Person Stops Drinking

  1. […] The 2nd reason can be especially important. When a person exceeds the “per day” limit (which is almost always consumed on a per occasion basis), they run the risk of drinking more than their brains and body can process. This, in turn, causes them to engage in drinking behaviors (e.g., getting into fights, arguments about the drinking, driving while impaired, having unprotected or unwanted sex). Check out these related posts, “I’m Sorry, but I was wasted,” “Why BAC Can Keep Rising After a Person Stops Drinking.” […]

  2. Jane Harris says:

    Hey Lisa!
    This is a great article, I had no idea that your BAC can continue to rise once you stopped drinking. I shared it on my Facebook page, which I hope you could take some time to look at and maybe even Like.
    Thanks a lot! Have a great day!

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