Blacking out from Alcohol: Causes and Dangers

Blacking out from Alcohol: Causes and Dangers

Do you often find yourself unaware of how you managed to come home after a particularly rough night of drinking? You probably have your friends to thank. After all, they were the ones who carried (if not dragged) you during your blackout.

What is a Blackout?

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What happens when you blackout from drinking excessive alcohol?

According to the National Institute on Alcohol Abuse and Alcoholism, a blackout is a partial or complete loss of memory. It is characterized by episodes of anterograde amnesia. This means alcohol affects the formation of memories that occur during intoxication, but not the ones that were ‘formed’ before it.

A blackout is usually brought out by excessive consumption of alcohol at a very rapid pace. It can also occur when a person drinks on an empty stomach, as this can lead to an immediate increase in blood alcohol concentration (BAC).

According to E.M. Jellinek, blackouts are powerful indicators of a person’s alcoholism.

Who is at Risk of Blacking Out?

Unfortunately, blackouts frequently occur in social drinkers. Several kinds of research have shown that social drinkers experience at least one instance of blackout during their lives. This is often due to their inexperience. Since they drink alcohol too quickly, their BAC levels rise easily to the point of blacking out.

College drinkers are also at risk. This is especially the case during the first 6 weeks of school, which the National Institute on Alcohol Abuse and Alcoholism cites as the most crucial. The widespread availability of liquor, coupled with peer pressure and limited interactions with ‘enforcing’ adults are some of the reasons why college students binge drink – and black out most of the time.

How Excessive Alcohol Consumption Affects Memory

Alcohol is known to affect memory. After all, it targets the hippocampus, the part of the brain that governs the formation of new memories.

When alcohol is consumed, the formation of new long-term memories is disrupted. The person, however, is still able to maintain the long-term memories he has formed before that.

Similarly, an intoxicated person can retain new information for a brief time. A study has shown that those who drank were able to recall new information for a short time – unless he is distracted.

More Alcohol = More Memory Gaps

A blood alcohol concentration of less than 0.15 can lead to small to moderate memory gaps – such as forgetting what the other person said a few minutes ago. Experts refer to these as “cocktail party memory deficit,” as this usually occurs after a few drinks. When this occurs, the person is unable to recognize new faces – or remember items from a list.

However, as more alcohol is consumed, memory impairment becomes more severe. As the intake continues, the intoxicated person can suffer from a blackout – an inability to remember events (parts of it or the entire thing) that happened during the said period.

Types of Blackouts

There are two types of alcohol-related blackouts. One is the en-bloc blackout. The person is unable to remember any detail that happened during the event, despite other people reminding them of what they did. In some cases, people carry on conversations – but could not remember what they said a few minutes before.

The second one is called a fragmented blackout. This is characterized as a ‘partial’ memory block. The person can’t recall some items – although he can recollect them once he is reminded.

The Dangers of Blacking Out

Because of the loss of memory that occurs during blackouts, this temporary phase of amnesia proves to be dangerous for men and women alike. White and colleagues interviewed 772 college students, with 9.4% of them admitting to having ‘blacked out’ in school. Unfortunately, they engaged in high-risk activities that they don’t remember doing.

Just like these college kids, a person who blacks out may end up doing the following:

Drunk Driving

Driving when drunk is a sin that most alcoholics commit. According to the National Highway Traffic Safety Administration, this leads to as many as 30 deaths per day. After all, alcohol can affect muscle coordination and reasoning. As with the case of blackouts, memory is affected as well. With these changes, alcohol can lead to loss of limb and life.

Unprotected sex

Alcohol is notorious for lowering one’s inhibitions. As such, it dulls a person’s ability to make smart decisions. One ‘poor’ decision that often stems from excessive alcohol consumption is unprotected sex. According to a study by Rehm et al., a BAC of 0.1 can increase the likelihood of having unsafe sex by as much as 5%. To wit, the more alcohol is taken, the higher the risk of having unprotected sex.

The consequences are magnified even more in a person who has blacked out. He/she might not be able to remember the deed – or he/she did it with. This can lead to an unprecedented transmission of sexually transmitted diseases, and unplanned pregnancy for women.

Legal problems

Alcohol can make a person more aggressive and violent – and such can explain the legal problems that hound an intoxicated individual. In fact, the book “Reducing Underage Drinking: a Collective Responsibility” links alcohol consumption with 36% of homicides, 12% of male suicides, and 8% of female suicides.

Apart from the mentioned figures, 50% of violent crimes have been attributed to alcohol. Rapes, robberies, and other assaults are just some of the crimes that have been committed due to alcohol intoxication or blackouts.

Spending money

According to an interview with London-based doctor Seth Rankin, blacked-out individuals tend to spend more because they ‘forget’ their bills. A drunk person is often more compulsive, which explains why blacked-out people spend more money than they are supposed to.

An intoxicated individual also tends to be more social. With this alcohol-induced friendliness, a drunkard may end up spending his/her money on drinks for everybody!

Property destruction

Vandalism and damage to property are just some of the dangers that come with an alcohol blackout. Intoxication leads adolescents – even college students – to destroy properties. Again, this can be attributed to alcohol’s ability to affect one’s inhibition and judgment.


Excessive and rapid alcohol intake can lead to blackouts or temporary memory loss. The consequences of this event are drunk driving, unprotected sex, legal problems (crimes), excessive spending of money, and property destruction, to name a few.

Latest posts by Raychel Ria Agramon, BSN, RN, MPM (see all)

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