Alcohol Blackout: Signs, Causes and Risks

Last Updated: September 22, 2023

Drinking so much that you cannot remember events from the night before might seem funny in movies or on television, but in reality, the experience can be frightening. Alcohol blackout experiences can result in you being in a dangerous situation, or you might even find out that you have done something you might regret for the rest of your life while not remembering any of it.

Blackouts can last anywhere from just a few minutes to several hours. Anyone can experience them. These slips in memory can indicate a more serious issue with alcohol, and there may even be some serious short and long-term effects.

What Causes an Alcohol Blackout?

There are many misconceptions about blackouts and their causes. Some people are quick to state that a certain type of alcohol — such as tequila or rum — causes blackouts or that only people with a low tolerance to alcohol have these experiences. Neither is true.

According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), there are two primary types of blackouts: fragmentary and complete or “en bloc” blackouts. A fragmentary blackout involves details missing from events or a fuzzy memory; these are sometimes referred to as “brownouts.” Complete blackouts are characterized by a total loss of memory despite being awake and functioning.

Blackouts occur not from drinking a certain type of alcohol but from drinking too quickly. When you drink slowly, your body and brain have time to adjust. It is impossible to predict exactly what alcohol levels will cause blackouts; however, fragmentary blackouts can begin with a blood alcohol content (BAC) of about 0.20 g/dL, which is grams per deciliter of blood. A complete blackout can begin at a BAC of around 0.30 g/dL.

Most blackouts occur due to binge drinking. This involves drinking five or more drinks in two hours for men or four or more in two hours for women. Binge drinking rapidly raises your blood alcohol levels, increasing them to the level needed to create a blackout.

Can You Prevent Alcohol Blackouts?

The only way to definitely avoid an alcohol blackout is not to drink high quantities of alcohol. However, you can use several other strategies to help reduce your risk of blackouts.

  • Set limits: Drinking too much can cause a blackout. You can avoid blackouts by setting a clear limit on how many drinks you will have during a specific timeframe and sticking with it.
  • Drink slowly: A healthy person metabolizes a drink in about an hour and a half. Because of this, drinking five drinks, each spaced two hours apart, is very unlikely to cause a significant rise in your BAC, while drinking the same five drinks all at once will.
  • Don’t drink on an empty stomach: Alcohol absorbs more slowly if you have food in your stomach. Drinking on a full stomach can give your body more time to metabolize alcohol and reduce the risks of an alcohol blackout.
  • Know your limits: Everyone is different. Certain medications can make alcohol last longer in your bloodstream, and women metabolize alcohol more slowly than men. Knowing how alcohol affects you can help you avoid drinking too much.
  • Have someone hold you accountable: Having a plan is nice but can be difficult to stick to in the moment. Having someone keep you accountable can help you avoid drinking too much and having a blackout.

How Blackouts Impact Your Brain and Body

According to the NIAAA, alcohol can interfere with your brain’s ability to form new long-term memories. The more you drink, the greater the chance of memory impairment. During a blackout, activity in the brain’s hippocampus becomes disrupted, a region of the brain that plays a major role in forming new memories. While your short-term memory can remain active, these new memories are not being stored in the brain and can never be recalled.

Something that is not discussed enough is the risky behavior that often occurs during a blackout. Not only does alcohol inhibit memory but also rational decision-making. A person in a blackout might decide to drive drunk, go home with a stranger or do something dangerous or unhealthy, with little to no memory of their actions the next day.

Ultimately, blackouts don’t specifically cause damage to your brain or body beyond inhibiting the formation of new memories during the blackout. They can, however, cause serious problems if illegal activities, intercourse or other risky behaviors take place during the blackout period.

While blackouts may not directly cause damage, it does take a very high BAC to cause a blackout. A BAC this high can increase your risks of injury, kidney damage, immune system suppression and even fatal alcohol poisoning. While a blackout might not be dreadfully dangerous, it indicates a level of drinking that can be.

Blackouts and Alcohol Use Disorder

Blackouts do not necessarily mean that you have an alcohol use disorder. Alcohol blackouts are common among social and college drinkers who may be more likely to binge drink. While blackouts might be temporary memory losses, evidence suggests that repeated blackouts can be troubling.

People with an alcohol use disorder often experience more blackout experiences than those who do not have drinking problems. Over 15 million people in the U.S. struggle with an alcohol use disorder, a chronic disease with short and long-term health consequences.

If you cannot control your drinking or experience frequent blackouts, it is time to take a closer look at your situation. At Orlando Recovery Center, medical professionals provide qualified and compassionate alcohol addiction treatment that can help you begin your journey to recovery.

Contact Orlando Recovery Center to speak with a Recovery Advocate about your situation and learn more about your options for admission.

Get your life back

Recovery is possible. Begin your journey today

Call Us Now Admissions Check Insurance

What To Expect

When you call our team, you will speak to a Recovery Advocate who will answer any questions and perform a pre-assessment to determine your eligibility for treatment. If eligible, we will create a treatment plan tailored to your specific needs. If The Recovery Village is not the right fit for you or your loved one, we will help refer you to a facility that is. All calls are 100% free and confidential.

All calls are 100% free and confidential.