Being blackout drunk means you drank enough that your brain stopped recording memories, even though you stayed awake. You were walking, talking, maybe texting or driving, and none of it got saved. According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), alcohol temporarily blocks the transfer of memories from short-term to long-term storage.
So the next morning there’s a hole. Sometimes it’s a few blurry minutes. Sometimes it’s the whole night, and you’re piecing it together from your phone, your bank app and the look on someone’s face.
What Does Blackout Drunk Mean?
A blackout is a gap in memory for things that happened while you were intoxicated. The important word there is happened. During a blackout you’re still functioning. You can hold a conversation, order another round, argue, laugh, get in a car. Friends might not have noticed anything strange beyond you being very drunk.
That’s what separates it from passing out. Passing out means losing consciousness; you’re not doing anything. Blacked out means you were doing plenty, and your brain just wasn’t writing it down.
Brownouts vs. En Bloc Blackouts
NIAAA describes two types.
Fragmentary blackouts are the more common kind. People call them grayouts or brownouts. You remember pieces: walking into the bar, a song, a face. Between those islands are stretches of nothing. Sometimes a reminder (“you sang karaoke”) brings a scrap back.
En bloc blackouts are complete. Hours are simply gone, often from a certain point in the night until you woke up. Those memories usually can’t be recovered, because they were never stored in the first place. To you, the events didn’t happen at all.
What’s Happening in Your Brain
The hippocampus is a small structure deep in the brain that takes what’s happening right now and files it for later. Alcohol interferes with it. NIAAA links blackouts to a rapid rise in blood alcohol, the kind you get from drinking quickly, so the speed matters as much as the total.
Alcohol is a depressant, and memory formation is one of the things it disrupts. Walking and talking can keep going after the recording has stopped, which is how someone can seem fine to the people around them and remember none of it.
Who’s Most Likely to Black Out
Anyone who drinks can black out, regardless of age or how experienced a drinker they are. NIAAA says the risk climbs when you:
- Drink on an empty stomach
- Drink fast, like shots or drinking games
- Binge drink
- Mix alcohol with medications for sleep or anxiety
Women appear to be at higher risk. On average they weigh less and have less body water, so each drink pushes their blood alcohol higher, faster. Two people drinking the same amount at the same pace can end the night in very different places.
Why Blackouts Are Dangerous
The memory gap is the least of it. During a blackout you’re still making decisions, just with almost no judgment and no record. People drive. They fall down stairs. They have sex they can’t remember agreeing to, or can’t remember refusing. They get into fights or get robbed. Among college students and young adults, NIAAA reports that frequent blackouts predict other fallout: missed classes and work, lower grades, injuries, ER visits and arrests.
A blackout also means blood alcohol got high, and high enough can kill. NIAAA notes that at high levels, blackouts can give way to passing out and death. Call 911 right away if someone who’s been drinking shows any of these signs:
- Confusion or stupor
- Can’t stay awake, or can’t be woken up
- Vomiting, especially while barely conscious
- Seizures
- Slow breathing (fewer than 8 breaths a minute) or long gaps between breaths
- Clammy skin, very low body temperature, or bluish or pale skin
Don’t wait for all of them. Don’t let them “sleep it off” alone, and turn them on their side if they’re lying down.
Is Blacking Out a Sign of Alcoholism?
Not automatically. NIAAA says blackouts aren’t necessarily a sign of alcohol use disorder, but even one is a reason for concern. It means you drank more, or faster, than your body could handle.
If they keep happening, it’s time for a harder look. Some questions doctors use to screen for alcohol use disorder:
- Have you ended up drinking more, or longer, than you meant to?
- Have you wanted to cut down and couldn’t?
- Have you kept drinking even though it caused trouble with family or friends?
- Have you needed more to get the same effect?
- Have you had shakiness, sweating or trouble sleeping when alcohol wore off?
Two or more of those in the past year points toward a problem. If you’re not sure where you fall, our post on binge drinking vs. alcoholism lays out the difference.
The Morning After
Waking up with a blank where last night should be is frightening. Then there’s shame: texts you don’t remember sending, a friend who’s suddenly quiet. Plenty of people deal with it by drinking again. It works for a few hours.
A better move is telling one person the truth, a friend, a pastor, a doctor. You don’t have to have it all figured out to say “this keeps happening and it scares me.”
Frequently Asked Questions
Can you remember a blackout later?
Sometimes, with a fragmentary blackout, a cue brings a piece back. With an en bloc blackout, the memories were never stored, so they usually don’t come back.
How much do you have to drink to black out?
There’s no set number. It depends on how fast you drink, whether you’ve eaten, your body size, your sex and any medications. Drinking quickly is one of the biggest factors.
Is blacking out the same as passing out?
No. Passing out is losing consciousness. During a blackout you’re awake and active; you just won’t remember it.
Do blackouts damage your brain?
A blackout is a sign that alcohol has disrupted how your brain works, and repeated heavy drinking can harm the brain over time. If blackouts are a pattern, talk with a doctor.
Alcohol Treatment at Covenant Hills
Covenant Hills is a Christian-based treatment center in Orange County, California. We help clients arrange medically supervised detox, then offer treatment for alcoholism in a residential setting with faith-based and traditional tracks.
If blackouts have become part of your drinking, call 800-662-2873 for a free, confidential assessment.
