What Happens When You Black Out From Drinking?

Surely we’ve all heard the stories that start with, "I was having such a good time last night, but I don't remember how I got home." This is often met with a hearty laugh or two, and life goes on. There are even songs that praise drinking until blackout; in “Last Friday Night,” Katy Perry sang “It’s a blacked out blur / but I’m pretty sure it ruled.”

Blackouts from drinking are highly normalized in society, but they shouldn’t be. The truth is, blackouts are more than short-term memory gaps. They’re hazards to our well-being.

So what is a blackout, and what exactly is happening on a neurological level? What causes blackouts? And most importantly, how do we prevent blackouts?

What Is a Blackout?

First, let's take a moment to understand what's really happening in our body and brain when we experience a blackout.

A blackout is not about “passing out” — losing consciousness or falling asleep — on the couch. It’s not only about forgetting parts of a drunken night. A blackout involves a significant disruption in the brain's memory creation process due to alcohol.

Imagine you’re a journalist conducting an important interview for an article. A blackout is similar to realizing, the next morning, that none of your important conversation saved –– even though you thought you pressed “record” and may still have the vaguest sense of what was said.

In a blackout, it's as if our brain has hit the "pause" button on its memory-recording function. This happens because alcohol, particularly in large quantities, interferes with the hippocampus, the part of our brain responsible for creating new memories.

When the hippocampus creates new memories, it transfers them from short- to long-term memory storage. Excess drinking in a short period of time blocks this transfer. As a result, we experience temporary memory loss.

Different Types of Blackouts

When we black out from drinking, we're experiencing a temporary form of amnesia. Try as we might, we simply can't recall events that occurred while we were intoxicated.

There are two types of blackouts, depending on how severe the impairments to our memory:

1. Fragmentary blackouts. In this type of blackout, memories are recalled as “islands” or isolated clusters with missing periods of time in between. You may remember ordering another shot, or fiddling with the lock on your door, or watching a friend get into an Uber, but can’t quite put it together. Some people also know this type as a “brownout.”
2. “En bloc” blackouts. These blackouts mean complete amnesia, in which the entire episode is blocked out. Since memories were not at all made during this timespan, none can be recovered. Someone in the middle of an en bloc blackout will likely be able to hold a conversation and recall things that have happened in the past couple minutes, but once they sober up the entire episode will be missing.

Both types of blackouts can lead us to perform actions we later regret, such as sending drunk texts or getting into arguments. We may also experience anxiety as a result of not remembering anything from the night before.

Of course, blackouts can be dangerous for many reasons — we may lose important items (such as our wallet or keys) or even get into confusing or unsafe situations. Aside from the immediate dangers, repeatedly blacking out can lead to a cycle of shame, regret, and mental health struggles.

Why Do I Black Out When I Drink?

Here's a surprising fact: we don't necessarily have to be falling-over-drunk to experience a blackout. Research shows that blackouts can occur after consuming just 3-4 drinks in an hour, especially on an empty stomach. That's about the equivalent of three glasses of wine or three bottles of beer.

We may not be falling down from this amount of alcohol, but it is considered binge drinking. When we drink in excess within a short time frame, our bodies struggle to process the alcohol, leading to a rapid rise in blood alcohol concentration (BAC). Because alcohol affects men and women differently, due to body size and composition, the definitions of binge drinking differ as follows:

• Men. For those assigned male at birth, 5 or more drinks in about 2 hours.
• Women. For those assigned female at birth, 4 or more drinks within 2 hours.

Special note for transgender and nonbinary people: There are no standard guidelines or definitions of drinking levels for transgender and nonbinary individuals. Generally, drinking level guidelines from doctors will depend on the duration of hormone therapy (if any) and other genetic and health factors. However, based on estimates from researchers and advocates utilizing a combination of measurements, binge drinking in the trans population seems to be higher than in the cisgender population.

Ultimately, someone can black out on a surprisingly “normal” amount of alcohol — everyone is different, and every drinking situation is different. Remember, it's not just about how much we drink, but how quickly we drink. Downing our drinks rapidly spikes the alcohol level in our bloodstream. This spike overwhelms the hippocampus, disrupting the memory and leading to a blackout.

Risks of Blackouts From Drinking Alcohol

While we might be tempted to shrug off a blackout as a one-time event, frequently getting blackout drunk could point towards a larger issue. Chronic heavy drinking can lead to severe health issues: liver disease, heart disease, and an increased risk of certain cancers, just to name a few.

In addition to physical health risks, blacking out can also place us in risky or outright dangerous situations. For instance, consider driving home after a night out. Our brain is functioning without the ability to form new memories, impairing our decision-making ability and potentially leading to disastrous outcomes — crashes, DUIs, or worse.

When do we know when our drinking might be problematic? We might believe that we're just social drinkers, enjoying a couple of glasses with friends. However, if we're frequently waking up with hazy memories or unexplained bruises, it might be time to reassess our relationship with alcohol.

Experiencing frequent blackouts is a sign that our drinking is problematic: we’re consistently consuming alcohol at a level that is physically altering how our brain works. The long-term risks are not worth the temporary fix for which many of us turn to alcohol.

How To Stop Getting Blackout Drunk

Blacking out isn't just about a forgotten drunken night; it points to a deep relationship between our brain, our behavior, and the outcomes of our life.

If we feel our relationship to drinking has become overwhelming, the key lies in recognizing, understanding, and taking steps towards change.

We're not powerless in the face of this challenge. A good first step is to keep an eye on how much we're drinking, how often, how quickly, and what emotions surround our decision.

Seeking community and professional help may be crucial if we're struggling to manage our drinking habits on our own. If you’re worried for yourself or someone you love, help is available. Reach out! Your long-term well-being is always worth it.