Alcohol, Blackouts, and Your Brain

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It’s common to want to unwind with a few drinks. Maybe you enjoy drinking a highball after a long workday, a few beers at the batting cage, or cocktails at the club. There isn’t anything wrong with moderate, responsible drinking, but sometimes alcohol overdose can occur, and the results are severe.

When you drink heavily on five or more days within 30 days — you may be at risk for developing a dependence on alcohol, or experience an alcohol overdose. Heavy alcohol use is defined as 5 or more drinks within a few hours for men, or 4 or more drinks within a few hours for women. One drink is defined as 1.5 ounces of liquor or spirits such as vodka or whiskey, 5 ounces of wine, 8 ounces of malt liquor, or 12 ounces of beer.

If you are dependent on alcohol, you may be craving alcohol when you don’t drink and have a difficult time limiting yourself to a few drinks. You may even find yourself out of control after a few alcoholic beverages. If this is the case, your overall health and well-being are at great risk — especially your brain, which can be changed and damaged with chronic drinking. Limiting your intake of alcohol can help you protect your brain from future harm.

Influencing Factors

It is a fact that drinking has far-reaching effects on the human brain. Short-term effects of alcohol on the brain include slurred speech, slowed reaction time, and memory impairment. Many long-term effects of alcohol on the brain can be so severe that a person requires around-the-clock custodial care.

Multiple factors determine how alcohol affects the brain and to what extent. These factors are: National Institute on Alcohol Abuse and Alcoholism identifies the following factors:

  • The amount of alcohol you drink
  • The frequency at which you drink
  • The speed at which you drink
  • Whether you have eaten recently
  • Your gender (women are more prone to blackouts)
  • The age at which you first began drinking, and how long you have been drinking since
  • Your age, education level, genetic background, and family history of alcoholism
  • Whether or not you are at risk due to prenatal alcohol exposure
  • Your general health status


After a few drinks, signs of alcohol impairment are usually highly obvious. The more you drink, the more impaired you become. If you drink high amounts of alcohol very quickly — especially on an empty stomach — you can experience a blackout. You may have experienced one or more blackouts in your life –  that you drink and later cannot remember the events that occurred during that period, the result of an alcohol overdose.

A high number of social drinkers are also binge drinkers, and face a higher risk for blackouts because they drink too much alcohol too quickly. Binge drinking is defined as consuming 5 or more drinks in 2 hours for men, and 4 or more drinks within the same time frame for women.

Why Do Blackouts Occur?

Alcohol interferes with the brain’s to form new long-term memories. It leaves established long-term memories intact and allows you to keep new information in your memory for a short period. This is why people can continue performing tasks and have conversations while in a blackout state — though later on, they may not remember anything about this time.

Alcohol attacks the hippocampus—a part of your brain that plays the central role in forming new memories for events. The more you drink, the more your brain is affected. The hippocampus sits in the center of your brain and receives information from many other regions of the brain. Somehow, the hippocampus connects all this information to form new autobiographical memories—memories of what happened to you. When you drink, you disrupt the hippocampus’ ability to do so.

Additionally, because the hippocampus operates in conjunction with other areas of the brain, alcohol, and drugs can further impair the hippocampus by affecting other parts of the brain.

When you drink to excess, you may experience what scientists call en bloc blackouts—stretches of time where you have absolutely no memory. Alternately, you may experience fragmentary blackouts—where the memory loss is spotty. Either way, your brain’s function is being changed by your drinking. Those changes can lead to permanent brain damage.

Blackouts Also Affect the Liver

Alcohol blackouts not only affect your brain but can impair your liver as well. Alcohol abuse causes your blood alcohol level to rise more quickly and stay high for a longer period. This can impair your liver as it works harder to try and break down excessive amounts of alcohol. When your liver is being overworked due to heavy alcohol use, it’s more likely you will experience a blackout.

If you frequently experience blackouts from drinking alcohol, it’s possible you may need help recovering from alcohol abuse. Seeking professional help today can help you maintain good brain health and prevent you from experiencing future blackouts.