What Is a Blackout?
A blackout is a temporary loss of memory brought about by heavy drinking. The individual experiencing an alcohol-induced blackout cannot remember events that happened while they were intoxicated.1 The degree of memory loss varies from one individual to another.
Different Types of Blackouts
According to a report in the National Institute on Alcohol Abuse and Alcoholism,there are two types of blackouts: partial (fragmentary) and complete (en bloc).1 An individual who has experienced a partial blackout may recall what happened when prompted by verbal cues. With a complete blackout, the memory loss is permanent. The individual is unlikely to remember events, even when others try to jog his memory.1
A blackout may last from a few minutes to several days. It ends when the body absorbs the alcohol, and the brain is able to form memories again. Sleep helps end blackouts, since rest gives the body time to process the alcohol.2
Even one blackout can be dangerous. The effects of alcohol increase the risk of injury from falls or accidents. While the individual may appear to be functioning normally, decision-making, judgment, and impulse control are impaired during a blackout. The individual may experience difficulty walking, talking, standing, and seeing.1
What Causes Blackouts?
Blackouts are caused by drinking too much alcohol too quickly. Alcohol interferes with the brain’s ability to form new long-term memories. As more alcohol is consumed and the blood alcohol level rises, the degree of memory loss increases.
It is believed that blackout occurs when the blood alcohol level reaches 14% or more. However, there is no set number of drinks that results in a blackout. It depends on the amount of alcohol in each drink and how alcohol affects the individual. Other factors that come into play include weight, gender, the type of alcohol, and how quickly it is consumed.2
Who Is at Risk?
Blackouts may happen to anyone who drinks large amounts of alcohol, but there are certain groups who appear to be more susceptible than others. Research suggests that middle-aged males who have a history of alcoholism are more likely to experience blackouts.2 Also at risk are young adults in college, due to the heavy drinking habits prevalent among many college students. One study provides a sobering assessment of the consequences of alcohol abuse among the college-age population:3
- Acquaintance rape victimization or sexual coercion
- Verbal or physical fights
- Personal injuries or injuring other people
Blackouts can occur in people who are clinically dependent on alcohol and in those who drink occasionally. In addition to abstaining from alcohol, exercising moderation and pacing oneself while drinking can help prevent a blackout:
- Eat a meal or appetizers before drinking alcohol. Drinking on an empty stomach increases the risk of blackout.
- Drink a glass of water between alcoholic beverages to limit the amount and rate of alcohol consumption.
- Drink slowly.
- Avoid “binge drinking.” Bingeing is defined as having 5 or more drinks in 2 hours for men and 4 or more drinks in 2 hours for women.2
Although many people recover completely from blackouts, the risk of experiencing another one remains as long as the underlying cause is not addressed. Individuals suffering from frequent blackouts should consider seeking help and getting treatment through a private inpatient or outpatient treatment center. Treatment is essential because there are devastating long-term consequences from alcohol abuse. Just one episode of blackout can result in serious injury or death.
- White, A.M. (2003). What Happened? Alcohol, Memory Blackouts, and the Brain. Alcohol Research & Health, 27(2), 186-196.
- Perkins, H.W. (2002). Surveying the Damage: A Review of Research on Consequences of Alcohol Misuse in College Populations. J Stud Alcohol Suppl, (14), 91-100.
- Birch, J. (2018). When You’re Blackout Drunk.