When someone drinks so much alcohol that he or she experiences amnesia in the morning, this is known as “blackout drinking.” As you might imagine, blackout drinking can be extremely dangerous, and it can be a sign that someone has an unhealthy relationship with alcohol which needs to be addressed. After a period of blackout drinking, a person may feel confused, disoriented, or distressed because he or she cannot remember events of the previous evening.

Blackout drinking does not necessarily cause people to lose consciousness or “pass out.” Instead, high alcohol consumption temporarily interferes with the function of the brain, causing the brain to be unable to retain information in short term memory. Many people do lose consciousness at the tail end of a period of blackout drinking, but it is possible to do plenty of mischief while awake. Upon regaining consciousness, the drinker may not know where he or she is or what is going on.

There are two main ways in which blackout drinking can impact the memory. In some cases, blackout drinking results in a large chunk of “lost time,” and the drinker will be able to remember events before and after the missing block of memory. The skipped events in the middle are a clue that a blackout was experienced. It is also possible to lose only fragments of memory.

Because blackout drinkers lose all memory of the events which occur during a blackout, they are at serious risk. Women may find themselves taken advantage of and be unable to remember the event, for example, or someone may get into a fight and wake up confused about the injuries sustained. On a less serious level, a blackout drinker make a promise to do something or meet up with someone during the period of blackout and then fail to follow through, which can strain friendships.

The amount of alcohol required to induce a blackout varies, depending on someone's weight, mental status, and diet, among other things. Some people appear to have a genetic predisposition to blackout drinking which can be make them more susceptible, and even hardened drinkers can experience a blackout after consuming an amount of alcohol which they think is normal. Repeated blackout experiences are a sign that someone may be alcoholic, and he or she should seek counseling.