How Blackouts and Brownouts Affect the Body

People who drink to excess may be subject to blackouts or brownouts. The former refers to a complete amnesia about events that occurred during episodes of binge drinking, while the latter means that memories of those events are hazy or partial. Ultimately, people who experience frequent memory loss related to drinking should be evaluated for alcohol dependency, and they may need substance abuse treatment to overcome their drinking problems.

Many people experience a retroactive loss of consciousness as a result of excessive alcohol consumption. When they wake up in the morning, they have no recollection of what happened while they were under the influence of alcohol the previous day. Or, their memories are hazy and dim, and they’re only able to remember a part of what occurred.

When the amnesia associated with heavy drinking is complete, this is referred to as a blackout. This state should not be confused with a loss of consciousness: the person experiencing the blackout simply cannot remember where they were, who they were with, or what they did or said during when they were under the influence of alcohol.

Meanwhile, when the memory loss is only partial, this is known as a brownout. Brownouts are less extreme versions of blackouts, with a degree of amnesia that is more limited. Details of what happened while intoxicated are missing, and the memories that remain are somewhat vague and distorted.

In the brownout vs. blackout comparison, blackouts are undoubtedly more significant and indicative of heavier alcohol use. But both are the result of a brain that has short-circuited, and each is a warning sign of dangerous and reckless behavior that could have serious long-term consequences if it continues.

Why Do Blackouts and Brownouts Occur?


Blackouts and brownouts are a side effect of binge drinking.

When people consume vast quantities of alcohol quickly, it can cause blood-alcohol content (BAC) levels to soar, and that can have a dramatic impact on neurological activity, specifically in the hippocampus.

The hippocampus is an area of the brain associated with long-term memory. Heavy alcohol consumption acts like a shock to the system, and when concentrations of alcohol in the blood reach a certain level, the hippocampus will stop functioning. The capacity to store long-term memories will be lost for an indefinite period, until the liver is able to successfully detoxify the bloodstream of the alcohol that saturates it.

Binge drinking is classified as the consumption of either four (for a woman) or five (for a man) alcoholic drinks within two hours, with a BAC of .08 as the projected level of intoxication. But the BAC threshold for a brownout is somewhere between .14 and .20, while the threshold for a blackout may be as high as .30, or nearly four times the expected BAC during an episode of “normal” binge drinking. To reach these astounding levels of intoxication the drinking must be fast and furious, and it is the sudden rush of alcohol into the bloodstream that causes the hippocampus to go into shutdown mode.

At the time of the actual drinking, the intoxicated person will continue to move around, make decisions, interact with others, and perform a variety of tasks including some that are complex. Memories will be retained from moment to moment, and while there will be clear signs of intoxication the person will still be able to function.

But when the following day arrives, their memories of these events will be non-existent, or foggy and incomplete if their hippocampus had been only moderately restricted by a brownout. Either way, blackout or brownout, these experiences are signs of serious neurological disruption and indicative of the type of damage binge drinking can cause.

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The Effects of Binge Drinking on Long-term Health


Blackouts and brownouts are not in themselves dangerous. But they are a sign of binge drinking out of control, and if it becomes a regular habit binge drinking can have destructive effects on a person’s health.

This is largely because of the effect of heavy drinking on the liver. Overstressed livers release harmful byproducts into the bloodstream when detoxifying the body of profound amounts of alcohol.

Some of the possible long-term consequences of binge drinking include:

  • Liver disease
  • High blood pressure
  • Heart disease
  • Stroke
  • Ulcers
  • Gout
  • Cancer (of the breast, esophagus, throat, mouth, colon, or liver)
  • Worsening of diabetes
  • Having children born with fetal alcohol syndrome
  • Permanent neurological damage that affect learning and memory
  • Overdoses (alcohol poisoning), accidents, or exposure to violence, any of which could prove fatal
  • Alcohol use disorders

In 2016, 65.3 million Americans age 12 and over admitted to episodes of binge drinking in the previous 30 days. Meanwhile, 15.1 million Americans had an alcohol use disorder in that same year.

Binge drinking and alcoholism are both dangerous, but when the two are combined the risks of health problems and other severe consequences rises significantly.

Evaluation and Treatment for Alcohol Dependency


Binge drinking is hazardous in any circumstances, but the heavy binge drinking associated with blackouts and brownouts is especially risky.

If binge drinking behavior continues indefinitely, debilitating and potentially deadly health problems are all but inevitable. The level of intoxication associated with blackouts and brownouts can also lead to reckless, impulsive, or irresponsible behavior that ends in tragedy—for the person with the drinking problem, their loved ones, or innocent bystanders.

Anyone who has experienced multiple episodes of memory loss caused by binge drinking should be evaluated for substance abuse, and they should be prepared to seek treatment immediately if they receive a diagnosis for an alcohol use disorder. Binge drinking isn’t synonymous with alcoholism, but people who are unable to control their binge drinking on their own clearly need help, which residential treatment centers that offer inpatient and outpatient treatment programs for alcohol dependency are ready, able, and willing to provide.