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Alcohol Blackout & Getting Blackout Drunk: Causes, Dangers & Prevention

Ever been blackout drunk or had an alcohol blackout? That is, have your memories after a night of binge drinking turned ‘dark’ after a certain point—whereby you’re seemingly on auto-pilot?

alcohol blackouts

Contrary to common assumptions, alcohol blackouts are a big deal and there’s nothing normal about the incidents. You should not shrug them off as part of the drinking culture. Studies show that drinking to the point of losing memory could have serious short-term and long-term consequences—including life-threatening accidents due to impaired judgement and risky behaviors.

According to a study published in the Journal of Addictive Behaviors, over 66% of university students have experienced blackouts at one time in their lives. Another similar survey showed that 2 in every 10 adolescents reported an alcohol-related blackout within the last 6 months. This goes to show that their occurrence is surprisingly common—making the issue more urgent.

It’s important to raise awareness of the risks associated with alcohol blackouts. With this in mind, read on for more on what causes the alcohol-induced blackouts, the different types of blackouts, risk factors, prevention measures, and everything in between.

What is an Alcohol Blackout?

What does it mean when someone says they “blacked out” after indulging in heavy alcohol consumption?

The National Institute on Alcohol Abuse and Alcoholism (NIAAA) defines alcohol blackouts as “gaps in a person’s memory for events that occurred while they were intoxicated.” These memory gaps occur when there’s enough alcohol content in your blood to temporarily block memory consolidation – i.e., the transfer of memories from short-term to long-term storage in the hippocampus.

Speaking to SELF, Aaron White, Ph.D., who is a senior scientific advisor to the NIAAA director notes that “Alcohol reduces the amount of information that makes it to the hippocampus and shuts down neurons in the hippocampus that make memories…This creates a temporary void in the record-keeping system.” In other words, the memories you lost while blackout drunk can never come back because they were not stored in the first place.

Please note that an alcohol blackout is different from passing out. Yes, there is the possibility of passing out due to a large quality of alcohol in your system. But blacking out does not necessarily mean that you fall asleep or become unconscious. Most of the time you’re wide awake, interacting with others and engaging in normal behaviors such as holding conversations—just that your mind does not record the experiences.

The brain continues to process information as usual—but memory formation is blocked. People who are blackout drunk have been known to engage in all sorts of activities—including destroying property, driving themselves home, eating meals, or engaging in risky sexual encounters.

Different Types of Blackouts

As stated by NIAAA, there are two types of alcohol blackouts—distinguished by the level of memory loss. This includes:

  • Complete Blackout (En Block): This happens when the hippocampus is severely impaired and memory consolidation is totally disabled. You cannot recall events under any circumstances until your Blood Alcohol Concentration (BAC) drops to more manageable levels. This poses a serious safety risk since anything can happen during this period of ‘darkness’ and you can’t recollect any of it—even if you try to jog your memory.
  • Partial Blackouts (Fragmentary): Partial blackouts or “brownouts” occur when the memory consolidation is impaired—but not severely. It’s typically characterized by fuzzy memories that have certain details missing. For example, you may recall hailing an Uber to take you home—but not how you got to your bed. Or you may remember chugging beer, but not where it came from. Someone experiencing a fragmentary blackout may recall an experience when it’s prompted by a conversational or visual trigger.

What Causes Blackouts?

As a toxin, the alcohol you consume goes to the liver to be metabolized and filtered out of your system. Under normal circumstance, your body is able to filter roughly one alcohol unit (8g or 10ml of pure alcohol) every 60 minutes. When you binge drink—and your BAC increases rapidly—the liver gets overwhelmed, hindering its ability to process the alcohol safely.

As more alcohol circulates your bloodstream, it triggers chemical (neurophysiological) disruptions that affect the activity of neurons in the hippocampus. Some brain cells then manufacture steroids that block memory formation. At the same time, the amygdala (the brain region that warns us about danger) and the frontal lobe (reasoning area) are suppressed by alcohol.

Blackouts are basically caused by high levels of alcohol in your system. Keep in mind that the risk of being blackout drunk has more to do with the rate of alcohol consumption in a sitting than the total amount of alcohol consumed. Alcohol blackouts typically occur when your blood-alcohol concentration increases rapidly. The higher the amount drank during a binge drinking session the higher the severity of memory loss.

Blackouts often occur when your BAC reaches 0.15—which is nearly double the legal BAC limit of 0.08 in most U.S. states. A study appearing in the Journal of Forensic Science estimates that you have a 50-50 chance of being blackout drunk if your blood alcohol content hits the 0.22% threshold.

It’s also worth noting that there is no set amount of drinks that can cause a blackout. It largely depends on the ABV (alcohol by volume) of your drink. For example, 12 fl oz of regular beer with an ABV of 5% is comparable to 1.5 fl oz of shots with an ABV of 40%.

Signs and Symptoms of an Alcohol-Induced Blackout

How can you tell if someone is blackout drunk? As highlighted earlier, the brain of someone who is blackout drunk continues to process information normally. For this reason, it’s difficult to differentiate between normal intoxication behavior and blackouts. Here are some common indications that could be tell-a-tale signs:

  • An inability to maintain long conversations.
  • A blacked-out person is often easily distracted.
  • They tend to forget where they are or what they were doing a few minutes ago.
  • They engage in risky activities that are uncharacteristic of their behavior when sober or tipsy.
  • He/she has been binge-drinking—especially on an empty stomach or when dehydrated.
  • The person seems oblivious of other people or events in the immediate surrounding.
  • They tend to ask the same questions or make the same statements repeatedly.

Why Are Some People More Likely to Get Blackout Drunk?

It’s clear that the concentration of alcohol in the blood directly affects the occurrence of blackouts. But this does not explain why some people are at a higher risk of losing chunks of their memories than others—despite consuming the same amount/concentration of alcohol.

What makes some people more susceptible to alcohol blackouts? Here are some risk factors:

  • Age: According to the Substance Abuse and Mental Health Administration (SAMHSA), adolescents and young adults (12-20 years of age) are more likely to binge drink. This is partly due to the drinking culture in universities and colleges—plus the lack of experience on alcohol moderation (i.e. underestimating amount consumed and overestimating tolerance). And as discussed earlier, this occurrence raises concerns over their physical, emotional, and mental health in the long term.
  • Gender: According to a study by researchers affiliated to the Palo Alto University in California, men could handle 3 more drinks before blacking out than women. This assertion was supported by a similar Brazilian study appearing in the PLoS One journal, which showed that women were 13% more likely to blackout if they exceed their usual amount then men. This is likely due to the difference in physical size, the percentage of body fat, and the difference in hormones.
  • Genetic Factors: Some studies also point to the possibility of genetic differences as indicators of the risk of getting blackout drunk. A study in the Archives of General Psychiatry found that hereditary factors accounted for up to 57.8% of all blackout cases in over 1,000 pairs of twins. Another study from the University of Texas claims that a “family history of problematic alcohol use” plays a significant role in the risk of blackouts—with men shown to be more susceptible to the effects.
  • History of Alcoholism: Studies show that the frequency of alcohol consumption and binge drinking in the past play a role in the risk of getting blackout drunk.

Dangers of Alcohol Blackouts – Short-Term and Long-Term Effects


blackout drunk

Alcohol has profound effects on the body and brain. It leads to the deterioration of several body systems—including the skeletal, cardiovascular, digestive, reproductive, liver, and immune system. More specifically, here are some of the health consequences related to alcohol blackouts.

  • Risk of Changes to the Brain: In a 2018 animal study, Australian researchers found that heavy drinking may lead to changes in the brain. This is especially a major concern for young people who are more prone to blackouts from binge drinking. Another study appearing in Frontiers in Medicine suggests that the young brain is underdeveloped and more sensitive to the negative effects of alcohol than an adult brain.
  • Sexual Victimization: A study published in the Journal of Sex Research showed that women in a blackout state were at risk of engaging in risky sexual behavior and regretting it after they sobered up. This is primarily due to impaired judgement and vulnerability to perpetrators—which makes pressing charges over a lack of consent a challenge. In the U.S., laws on what constitutes sexual consent during alcohol incapacitation vary by state.
  • Risk of Physical Injuries and Accidents: A person who is blacked out may appear normal to outside observers. This increases their risk of freely engaging in risky activities—including driving while intoxicated, vandalizing property, and engaging in non-consensual, unprotected sex. Despite barely remembering the turn of events, these actions pose serious legal and health consequence—some life-threatening.
  • Mental Health Problems: People who are blackout drunk are at an increased risk of sexual assault and other traumatizing personal encounters. This can manifest in mental health problems such as PTSD (post-traumatic stress disorder) or depression.
  • Choking or Suffocation: The National Institute on Alcohol Abuse and Addiction notes that alcohol may delay autonomic responses such as gag reflex. This means that a person who is overdosed or blacked out from excessive alcohol consumption is at risk of choking on their vomit—especially if they pass out.
  • Increased Risk of Alcohol Poisoning: Alcohol blackouts usually happen when the BAC increases rapidly. When the alcohol concentration in your blood exceeds a certain threshold, you’re at risk of alcohol poisoning—which has serious repercussions. Some health risks due to alcohol poisoning include seizures, irregular breathing, profuse vomiting, hypothermia, severe dehydration, mental confusion, falling into a coma, and even death.

Does Getting Blackout Drunk Signal an Alcohol Use Disorder?

While excessive or binge drinking is dangerous, a person who experiences blackouts does not necessarily have a substance use disorder. It only means that they downed one too many shots in a sitting. Alcohol abuse disorder is indicated by regular/uncontrollable drinking and not the occurrence of blackouts.

But if you continually complain about losing your memory after a night out, then you might want to reconsider your alcohol consumption habits. People with frequent blackouts often have a higher tolerance for alcohol. This puts them at risk of addiction and alcohol poisoning.

In other words, alcohol blackouts are one symptom or early indicators of an alcohol use disorder. Other symptoms include:

  • Intense and seemingly uncontrollable cravings for alcohol.
  • Hiding or misleading others on the intensity of your drinking habits.
  • Mental and physical withdrawal symptoms if you attempt to reduce the amount you ordinarily consume.
  • Frequently engaging in risky behavior due to intoxication.
  • Reduced productivity and work or school.
  • Social and financial problems due to your alcohol consumption habits.

Alcohol Blackout Prevention

Even a single blackout incident could have serious repercussions. The most obvious—and effective—way to avoid the risk associated with alcohol blackouts is giving up alcohol consumption altogether. But if this isn’t a viable option, at least drink in moderation.

Passing yourself between drinks can help prevent blackouts. It gives your liver the much-needed time to safety metabolize and expel the alcohol toxin from your body. Consider monitoring your alcohol intake or asking friends to keep tabs on your drinking habits. However, this is easier said than done since some behaviors associated with being blackout drunk are often normalized or laughed off.

It’s also advisable to hydrate frequently while consuming an alcoholic beverage. This reduces the rate of consumption and concentration of alcohol in your system. Another useful tip is to eat before drinking. Food slows down the absorption of alcohol in your body—hence preventing a spike in blood-alcohol concentration.

Help is Available

If you or someone you care about is struggling with alcohol blackouts and binge drinking, it’s important to seek professional care as soon as possible. Early intervention increases the success rate of recovery—while minimizing the risk of relapse.

Oro House Recovery offers a comprehensive alcohol treatment plan—include medically-assisted detoxification, out-patient, and in-patient care. Our approach is compassionate—meaning we don’t judge or make you feel ashamed. And since we understand the challenges people face during their first steps of recovery, we provide a conducive environment to support your journey. We aim to empower our clients to be the best version of themselves.

To find out more about how Oro House Addiction Treatment Programs can help with alcohol addiction, call us toll-free at (888) 834-3949.

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Oro House Recovery Centers

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