Blacking Out Drunk: What Does It Mean and How Does It Happen?

Alcohol abuse poses severe risks to your well-being, with excessive drinking leading to potentially life-threatening situations. When someone drinks too much alcohol in a short period, they can experience dangerous changes in blood pressure, breathing rate, and body temperature. The risk of accidents, injuries, and poor decision-making increases dramatically.

Beyond the immediate dangers, repeated episodes of heavy drinking can damage vital organs, including the liver, heart, and brain. Long-term alcohol abuse often strains relationships, impacts work performance, and may develop into alcohol use disorder.

The Meaning of ‘Blackout Drunk”

A blackout from alcohol occurs when someone drinks enough to temporarily block the transfer of memories from short-term to long-term storage in the brain.[1] During these episodes, a person can still walk, talk, and engage in activities, but their brain isn’t creating new memories of these events. This differs from passing out, where someone loses consciousness entirely. The next day, they may not recall what happened during the blackout period, creating gaps in their memory that can be distressing and potentially dangerous.

The science behind blackouts involves alcohol’s effect on the hippocampus, a brain region crucial for forming new memories.[2] When blood alcohol levels rise quickly, the hippocampus becomes unable to form new episodic memories – the memories of what happened, when it happened, and where it happened.

The amount of alcohol needed to trigger a blackout varies from person to person, depending on factors like body weight, tolerance, drinking speed, and whether food was consumed.[3] However, blackouts typically occur at high blood alcohol concentrations, often above 0.15 percent. Women may be more susceptible to blackouts than men due to differences in how their bodies process alcohol. Medical experts emphasize that experiencing blackouts is a serious warning sign of dangerous drinking patterns and can indicate an increased risk of developing alcohol use disorder.

What is Alcohol Use Disorder?

Alcohol use disorder is a complex medical condition where a person develops an impaired ability to control or stop drinking despite negative consequences to their health, relationships, work, and daily life.[4] The condition exists on a spectrum from mild to severe, and it can affect anyone regardless of age, background, or social status.

While many people think of alcohol use disorder as simply “alcoholism” (an outdated, stigmatizing term), medical science now recognizes it as a chronic brain disorder that requires professional treatment and support.

Common signs and behaviors include:[5]

• Drinking more than planned: A person repeatedly drinks larger amounts or for longer periods than they originally intended, often losing track of their consumption during each episode.
• Failed attempts to cut back: Despite wanting to drink less or quit, they find themselves unable to reduce their alcohol intake even after making serious attempts.
• Time spent around alcohol: Much of their day revolves around obtaining alcohol, drinking, or recovering from drinking episodes, often at the expense of other activities they once enjoyed.
• Strong urges to drink: They experience persistent thoughts about alcohol and feel powerful cravings that are difficult to ignore or control.
• Impact on responsibilities: Their drinking begins to affect their performance at work or school, their ability to care for family, or handle other important obligations.
• Relationship strain: They continue drinking even though it causes or worsens problems with family members, friends, or romantic partners.
• Health problems emerge: They keep drinking despite knowing it’s causing or worsening physical or mental health issues, such as liver problems, depression, or anxiety.
• Risky behavior: They engage in dangerous activities while drinking, such as driving, swimming, or operating machinery.
• Tolerance develops: They need to drink more alcohol than before to get the same effect or notice that the same amount of alcohol has less impact than it used to.
• Withdrawal symptoms: When the effects of alcohol wear off, they experience symptoms like shakiness, sweating, nausea, or anxiety, often leading them to drink to avoid these feelings.

What Causes Blackouts When Drinking?

When blood alcohol concentration rises rapidly, alcohol begins to interfere with the brain’s memory formation process, specifically in the hippocampus. This interference disrupts the brain’s ability to convert short-term memories into long-term ones, leading to a blackout. During these episodes, the brain stops recording new experiences, even though the person may continue functioning, talking, and engaging in activities. This sudden rise in blood alcohol levels is often seen when people drink large amounts quickly or drink on an empty stomach.

The biological mechanism involves alcohol’s impact on specific neural receptors that play a crucial role in memory formation. Alcohol particularly affects NMDA receptors, which are vital for memory formation and learning.[6] When alcohol blocks these receptors, it prevents the strengthening of synaptic connections that typically occur when forming new memories. Additionally, alcohol enhances the effects of GABA, an inhibitory neurotransmitter, which further impairs the brain’s ability to create new memories. This is why someone experiencing a blackout may seem conscious and functional but later have no recollection of events that occurred during this period.

The Dangers of Blacking Out

Alcohol-induced blackouts represent a dangerous state that puts people at significant risk for both immediate harm and long-term consequences. During a blackout, a person remains conscious but loses the ability to form new memories, making them vulnerable to hazards while lacking the capacity to make sound judgments or recognize warning signs of danger:[7]

• Physical injuries and accidents: People experiencing blackouts often suffer falls, burns, cuts, or more severe injuries since their coordination and judgment are severely impaired.
• Dangerous behavior: Blackouts frequently lead to risky activities like drunk driving, swimming while intoxicated, or walking in unsafe areas without awareness of surroundings.
• Sexual vulnerability: During blackouts, people may become victims of sexual assault or engage in unprotected sexual activity they cannot remember or did not consent to.
• Alcohol poisoning: The high levels of alcohol needed to cause blackouts put people at risk for potentially fatal alcohol poisoning.
• Legal problems: People in blackout states might commit crimes, damage property, or face legal consequences without any memory of their actions.
• Brain damage: Repeated blackouts may cause lasting damage to memory formation and cognitive function, particularly in young adults whose brains are still developing.
• Emotional trauma: Waking up with no memory of events can cause significant anxiety, depression, and psychological distress.

Seeking Help For Alcohol Issues

Blackouts are a serious warning sign that drinking habits have become dangerous and require immediate attention. Taking action typically begins with acknowledging the problem and speaking with a doctor or addiction specialist, who can perform a comprehensive evaluation and recommend appropriate treatment options. These medical professionals can determine if someone needs medically supervised detox, outpatient counseling, support groups, or more intensive rehabilitation programs.

Recovery often requires a multi-faceted approach, including professional medical care, behavioral therapy, and strong support systems. Many people find success working with therapists who specialize in alcohol use disorder to identify drinking triggers and develop healthier coping mechanisms. Support groups like Alcoholics Anonymous or SMART Recovery provide valuable peer support and practical strategies for maintaining sobriety. It’s also crucial for someone experiencing recurring blackouts to be honest with trusted friends and family members about their struggles, as this support network plays a vital role in successful recovery.