Blacking Out Drunk: Understanding the Risks, Causes, and Prevention

Key Takeaways

• Blackouts occur when alcohol blocks memory transfer to long-term storage in the hippocampus, and they can begin at blood alcohol concentrations around 0.16 percent.¹
• Two types exist: fragmentary (partial) blackouts where some memories return with cues, and en bloc (complete) blackouts where memories are permanently lost.^1,2
• Women, college students, and binge drinkers may face a higher blackout risk due to body composition, drinking inexperience, and rapid BAC increases.^1,2
• Frequent blackouts may signal a pattern of unhealthy alcohol use and can increase risk of injury, assault, and other harms.^1,2

Some people talk about getting "blackout drunk" like it's a peak drinking experience. They may see it as proof the party felt wild or that they felt less inhibited. But getting blackout drunk can raise your risk of serious harm.

What Does It Mean to Black Out?

Blacking out drunk means you have a "blackout" period in your memory.¹ You may not remember what happened around you or to you during that time.^1,2 You're still awake when you black out, but your brain isn't forming new long-term memories.^1,2

Alcohol can cause two types of blackouts: partial and complete.^1,2 If you have a complete blackout, you won't remember what happened during that time, and it can feel like a blank space in time.^1,2 Partial blackouts mean you might remember some things, and other memories may come back with reminders or cues.^1,2

Both types of blackouts make it harder to form and recall memories during that period of drinking.^1,2

How Alcohol Affects the Brain and Memory

Blackouts affect an area of the brain called the hippocampus, which helps form new memories and move them into long-term storage.^1,2 Drinking a lot of alcohol in a short time can interrupt this process.^1,2 Alcohol also affects your body in other ways.³

Alcohol disrupts chemical signaling in your hippocampus.² This disruption can keep the hippocampus from storing events and memories as they happen.^1,2 Heavy, ongoing alcohol use can also contribute to alcohol-related brain damage.² Blackouts affect memories made while alcohol levels are high, rather than older memories from before you drank.^1,2

You may seem alert and able to hold a conversation during a blackout. But what happens may not stay in your memory for longer than a few minutes.²

Who's More Susceptible to Blackouts?

The severity of your blackout often depends on your blood alcohol concentration (BAC), which means the amount of alcohol in your blood. Blackouts often begin at BACs around 0.16%.¹ Higher BACs can make blackouts more complete.^1,4 Because of this, some groups may be more likely to black out, including women, young college students, and people who binge drink.^1,2

Women may be more likely to black out than men.¹ This can relate to differences in body size and body composition, as well as how alcohol breaks down in the body.¹ Some drinks, like wine and mixed drinks, can also contain more alcohol per serving than beer, depending on the pour.¹

College students and other young drinkers may experience blackouts more often.^1,2 Drinking experience can play a role, especially when someone drinks a lot in a short time.^1,2 Binge drinking, which usually means drinking enough to bring BAC to 0.08% or higher, can raise your BAC quickly and increase blackout risk.¹

Recognizing the Signs of Blackout Drinking

You may notice signs that someone is in a blackout.² Still, it can be hard to tell, including when it happens to you. Someone may seem okay and keep much of their movement and thinking skills, even though their memory isn't functioning normally.²

You can look for problems with memory. Many people have some trouble thinking clearly when they've been drinking. During a blackout, memory problems can stand out more because the person has trouble holding on to new information for more than a short time.² If you think someone may be in a blackout, getting them to a safe place and staying with them can help reduce risk.

Forgetfulness

Someone in a blackout may repeat questions, seem confused, or forget names, faces, or information they just learned.²

If you're trying to understand what's happening, you might ask them to name three items, like fruits. A couple of minutes later, you can ask them what they named. If they're forming memories, they may remember, even if their speech is slurred or it takes time to think. If they're in a blackout, they may struggle to recall the list.²

Retelling Stories

Your friend may repeat the same story because they don't remember already telling it.² They may also repeat the same update throughout the night, like noticing a mutual friend nearby.

Seeming Confused When Corrected

If you tell your friend they've already shared the same thing multiple times, they may seem confused.² They may not believe you. They may not realize their memory has started to slip during that time.²

Motor or Cognitive Impairment

If someone seems very intoxicated, you may notice stumbling, unclear speech, poor coordination, slurred speech, or sleepiness. This can signal a high level of intoxication, which may include a blackout.²

When to Intervene

If your friend, or anyone else, seems like they may be in a blackout, staying close to them can help. Alcohol can affect judgment and coordination, which can raise the chance of unsafe situations.^1,2 Helping them avoid driving can also reduce risk.¹ It can also help to stay with them, since an impaired person may be more vulnerable to harm from others.¹

You can invite your friend to stay near you. If they have trouble remembering, staying with them more closely may help keep them safe.

If it feels like the right choice for the situation, you can step away from the environment and go somewhere safer. This could mean going home if you're at a bar or going to a quiet room if you're at a party. You can also arrange a ride, like a taxi or rideshare, if driving doesn't feel safe.

Risks and Consequences of Blacking Out

Sexual and Physical Violence

Getting blackout drunk can raise your risk of physical and sexual violence.^1,2 You may go along with what someone else wants because alcohol can affect your judgment and memory.^1,2

If you have sex during a blackout, you may not remember if you gave consent, if your partner acted violently, or if you used protection. If harm happened, memory loss can also make it harder to explain what occurred when you seek medical care. This can apply to both physical and sexual assault.

Waking Up Somewhere Unfamiliar

After blacking out, you may wake up and feel unsure where you are, how you got there, or how to get home.^1,2

Acting Out of Character

You might get into trouble during a blackout. Alcohol can affect judgment, and you may take risks you wouldn't take when sober.^1,2 This can include illegal actions, which may lead to legal problems.

Causes and Triggers of Blackout Drinking

Blackouts often happen when you drink a lot in a short time, which causes your BAC to rise quickly.^1,2 This can happen during binge drinking or other high-intensity drinking patterns.¹

Some medicines and other substances, including sedatives and some anti-anxiety medications, can increase impairment when combined with alcohol. This may raise blackout risk at lower amounts of alcohol for some people.¹ Checking medication labels and talking with a pharmacist or prescriber can help you understand alcohol warnings.

Prevention Strategies for Blackout Drinking

Drinking less and drinking more slowly can lower your risk of a blackout.^1,3 You might set a limit, like about one drink per hour. Eating before you drink and having water throughout the night may also help.³ Drinking games and fast drinking can raise BAC quickly, which can increase blackout risk.^1,2

You can also alternate alcoholic drinks with water or another non-alcoholic drink. Planning your ride home ahead of time can also help. You might go with a friend who isn't drinking or set up a rideshare in advance.

If you're in a new or stressful setting, you may drink faster than you mean to. It may help to slow down, track your drinks, and keep your drink with you. Accepting drinks only from people you trust can also reduce risk.

Supporting Others and Seeking Help

One way to help a friend or family member who may be struggling with alcohol is by noticing patterns, like frequent blackouts or binge drinking. If you notice these signs, you can consider starting a conversation about how they're feeling and how alcohol fits into their life.

You can also start conversations early by talking with your kids and teens about blackout drinking and its consequences. You can share options that may help them stay safer, like pacing drinks, eating before drinking, and planning rides. If someone wants to cut back or stop, you can also share resources on how to taper off alcohol.

Start Your Recovery Journey

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