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What is Alcohol Blackout Syndrome?

An alcohol blackout — also known as alcohol-induced amnesia — is when a person’s memory is impaired due to alcohol intake or alcohol addiction. Alcohol blackouts are not the same as passing out or fainting. They are more like a temporary form of amnesia that makes a person forget events immediately following alcohol intake.
“alcohol blackout is when a person’s memory is impaired due to alcohol intake or or alcohol addiction.”
Statistics provided by Alcoholics Anonymous appear to suggest that blackouts are an indication of alcoholism, although this theory is not backed by any specific scientific studies. According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), victims of alcohol blackouts are most likely to be young adults and binge drinkers. Blackouts mean that individuals are more susceptible to engaging in high-risk behaviors that they may not even recall after the alcohol has worn off.


In certain circumstances, large amounts of alcohol can actually prevent a person’s brain from forming any kind of short-term memory. This means individuals are unlikely to ever recall what happened during the period of blacking out.

Various Causes of Blackouts

The risk of an individual experiencing a blackout increases once alcohol levels pass a certain point. Although the actual amount of alcohol will vary between individuals, it is most likely to happen when a person’s alcohol level reaches .15. This is extremely high when compared to the legal driving limit of .08. Despite this, some individuals may not feel the effects of alcohol at this level. Drinking quickly also increases a person’s chances of experiencing an alcohol blackout, because it takes the average human body an hour to process one drink.


Alcohol blackouts have been used in court cases as an excuse for criminal behavior. Individuals have claimed that they cannot remember committing offenses such as assault, vandalism, theft and drink driving because of excessive alcohol intake and blackouts.

What are Potential Risks?

The obvious risk associated with a blackout is that being under the influence of copious amounts of alcohol is not the best time to make important decisions. This situation not only puts the safety of the individual at risk but also that of other people around them. A person who would not normally drink and drive may decide to take the risk when under the influence. Being unable to remember events from the day (or night) before means that a person may be unable to recall potentially dangerous situations. An alcohol blackout is the body’s way of warning people they have had too much to drink.

How Long-Term Use Affects You

While it is true that most people will suffer at least one alcohol-induced blackout in their lifetimes, repeated blackouts can have a significant effect on an individual’s brain. According to the NIAAA, repeated alcohol blackouts can cause:

  • Permanent memory impairment
  • Impaired cognitive development
  • Behavioral problems
  • Brain damage


Studies carried out by a California University discovered that individuals who had suffered a head injury at some point in their lives were at a greater risk of blacking out. This was totally unrelated to the levels of alcohol in their system. Individuals who suffer from diabetes are also more prone to suffering an alcohol blackout.

The Relationship Between Alcoholism and Blackouts

Although alcoholics do usually suffer from frequent alcohol-induced blackouts, a person does not have to suffer from alcoholism to suffer a blackout. Blackouts are a direct result of how much alcohol a person drinks at once or in a single sitting and not of how much they drink over a longer time period. People who drink on a regular basis will naturally develop a higher tolerance to alcohol. This does not mean they will not suffer from blackouts, just that their alcohol levels will be a lot higher when the blackout occurs.

Unfortunately, there is no way of knowing how much alcohol an individual can tolerate. An alcohol level that may have no effect on one individual may have fatal consequences for another, making drinking large amounts of alcohol a very risky business.


Women who drink large amounts of alcohol are more likely to suffer medical consequences as a result than men. For example, more female alcoholics develop cirrhosis and other alcohol-related conditions than their male counterparts.

Take Preventative Steps

The only guaranteed way to prevent having an alcohol blackout is to not drink too much alcohol. Individuals should also stick to the same drinks and ensure their intake is even and not rushed. The University of New Hampshire advises individuals to have no more than two drinks every hour. People should also make themselves aware of the actual alcohol content of what they drink, as well as ensuring they stick within safe limits. If you believe you have a problem with drinking, please call our advice line at .


Individuals who suffer an alcohol blackout every time they drink should seek the advice of their physician. A condition called Wernicke-Korsakoff syndrome is defined by memory problems and learning difficulties. This condition most commonly develops in individuals who suffer from alcoholism or who drink heavily on a regular basis.

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