Memory loss after drinking can cause significant distress to those who experience it. Discover what causes alcohol blackouts, the different types and the risks associated with experiencing a blackout in this article.


What is An Alcohol Blackout?

An alcohol blackout, also known as an alcohol-related blackout, occurs when a person who has consumed a significant amount of alcohol experiences a period for which they have little to no memory afterwards. During a blackout, the person may engage in activities, conversations, and interactions, but they are unable to recall these events later, even when prompted.

The National Institute on Alcohol Abuse and Alcoholism explains that an alcohol blackout is essentially a gap in your memory when you are intoxicated. If you drink enough alcohol to temporarily block the transfer of memories from short-term to long-term storage, you will experience this gap in memory.

Alcohol blackouts are a result of the way alcohol affects the brain, particularly its impact on your memory. Alcohol interferes with the functioning of the hippocampus, a region of the brain crucial for converting short-term memories into long-term ones. If you consume an excessive amount of alcohol in a short period of time, the hippocampus struggles to encode new memories, leading to a memory gap for the period affected by the blackout.


Different Types of Alcohol Blackouts

There are two primary types of alcohol blackouts, differentiated by the severity of the memory impairment. The National Institute on Alcohol Abuse and Alcoholism explains that the most common type of alcohol blackout is ‘Fragmentary Blackout’, also known as Brownout. This is where the person has partial memory loss. They might recall some events or fragments of what happened during the blackout but have significant gaps in their memory.

The second type of alcohol blackout is called an ‘En Bloc’ Blackout and is essential to complete amnesia. In this type of blackout, the person cannot remember any events that occurred during the blackout period. It’s as if that period is completely missing from their memory.

It’s important to note that alcohol blackouts are a sign of potentially dangerous levels of alcohol consumption and are often associated with binge drinking or heavy alcohol use. Experiencing blackouts can also be an indicator of alcohol use disorder, which is a more serious and chronic condition involving problematic alcohol consumption.


What Causes Alcohol Blackouts?

Alcohol blackouts are primarily caused by the effects of alcohol on the brain, particularly its impact on memory formation. Healthline details that alcohol blackouts can also be caused by:

  • Epileptic seizures – during a seizure, the brain’s normal electrical activity is disrupted, which can affect memory formation and recall.
  • Fainting – fainting can result in a temporary loss of consciousness and memory gaps around the time of the fainting episode.
  • Certain medications – some medications, particularly those that affect the central nervous system, can cause memory impairments, confusion, or gaps in memory.
  • Low blood pressure – insufficient blood flow to the brain due to low blood pressure can lead to temporary cognitive impairments, including memory disturbances.
  • Low blood sugar – low blood sugar levels can impact brain function and lead to memory issues or confusion.
  • Oxygen restriction – lack of sufficient oxygen supply to the brain, as can happen during choking or suffocation, can result in cognitive deficits, including memory problems.

Other Known Causes of Alcohol Blackouts

Other factors that can influence the likelihood of experiencing an alcohol blackout include:

  • Drinking speed – consuming alcohol rapidly can increase the risk of a blackout. When alcohol is consumed quickly, blood alcohol concentration (BAC) rises rapidly, overwhelming the brain’s ability to process and form memories. The faster BAC rises, the more likely the hippocampus will struggle to encode new memories, leading to memory gaps.
  • Alcohol content – the concentration of alcohol you consume is a significant factor. Drinks with higher alcohol content, such as spirits and some cocktails, can lead to quicker increases in BAC compared to lower-alcohol drinks like beer or wine.
  • Body weight and metabolism – your body weight and metabolism play a role in how alcohol affects you. People with higher body weight may experience lower BAC levels for the same amount of alcohol consumed, as alcohol is distributed throughout a larger volume. Metabolism also influences how quickly your body processes alcohol.
  • Tolerance – those who drink excessive amounts of alcohol frequently may develop a tolerance to alcohol’s effects, which means they require more alcohol to achieve the same level of intoxication. This tolerance can influence the likelihood of blackouts, as individuals with higher tolerance might consume larger quantities of alcohol before experiencing memory impairments.
  • Previous experience – individuals who have experienced blackouts before might be more likely to experience them again, possibly due to changes in the brain’s sensitivity to alcohol’s effects on memory.


The Risks of Alcohol Blackouts

If you’re drinking in excess to the point of a blackout, you’re putting yourself at serious risk of social, mental, and physical problems. Alcohol blackouts commonly lead to accidents and injuries, violent behaviour, alcohol poisoning and long-term health issues.

During a blackout, you’re at a much higher risk of engaging in risky behaviours, such as driving under the influence, engaging in unsafe sexual activities, or even experiencing accidents due to impaired coordination and judgment. This can lead to injuries not only for the individual but also for others involved.

The long-term impact of alcohol blackouts could include liver damage (such as cirrhosis), heart problems, pancreatitis, gastrointestinal issues, and an increased risk of certain cancers.


Find Help For Alcohol Addiction Today

We hope you’ve found this article on what causes alcohol blackouts informative. If you’re struggling to control your alcohol consumption, here at Nova Recovery, we offer the expertise and resources to help you along your road to recovery.

Our professional team will assess your physical and psychological health to create a tailored recovery programme specific to your unique needs. If you’re suffering from alcohol addiction, we can suggest a carefully balanced treatment programme inclusive of cognitive behavioural therapy (CBT), dialectical behaviour therapy (DBT), motivational interviewing, stress management, relapse prevention therapy, and mediation therapy.

We also recommend several well-being therapies, such as mindfulness, yoga, low-level laser therapy, nutritional supplement therapy, fitness therapy, art therapy, relaxation and sleep management, and music therapy. A balanced combination of these therapies, tailored to the individual, will give you the best chance of achieving a long-term recovery from addiction. Reach out today for more information.

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John Gillen - Author - Last updated: September 8, 2023

John has travelled extensively around the world, culminating in 19 years’ experience looking at different models. He is the European pioneer of NAD+ (Nicotinamide Adenine Dinucleotide) treatment to Europe in 2010; and recently back from the USA bringing state of the art Virtual Reality Relapse Prevention and stress reduction therapy. His passion extends to other metabolic disturbances and neurodegenerative diseases. The journey continues. In recent times, John has travelled to Russia to study and research into a new therapy photobiomudulation or systemic laser therapy working with NAD+ scientists and the very best of the medical professionals in the UK and the USA, together with Nadcell, Bionad Hospitals own select Doctors, nurses, dieticians and therapists. Johns’ passion continues to endeavour to bring to the UK and Europe new developments with NAD+ Therapy in preventive and restorative medicine and Wellness. In 2017 John Gillen was made a visiting Professor at the John Naisbitt university in Belgrade Serbia.