How Alcohol Works

Alcohol Abuse

drunk guy passed out drunk guy passed out
Globally an estimated 237 million men and 46 million women have some form of alcohol-use disorder. skaman306/Getty Images

Globally an estimated 237 million men and 46 million women have some form of alcohol-use disorder, that's according to WHO's 2018 Global status report on alcohol and health.

In the United States, approximately 15.1 million adults ages 18 and older (6.2 percent of this age group) had alcohol use disorder (AUD), which is a chronic relapsing brain disease that involves the affected person compulsively using alcohol, losing control over their alcohol intake, and having a negative emotional state when they're not drinking. This includes 9.8 million men. In 2010, alcohol misuse cost the U.S. $249 billion.

Research has shown that alcohol use in general has risen in recent years, and problem drinking (which includes alcohol abuse, i.e. drinking to the point where it causes recurrent and significant life problems, and alcohol dependence, i.e. the inability to stop drinking) has risen by a greater percentage, particularly in women, racial minorities, older adults, and lower socioeconomic classes. With the continued exposure to alcohol, how does the human body respond or adapt? The body's increased tolerance to alcohol involves the following changes:

  • Increase in level of liver's enzymes that are used to break down alcohol
  • Increase in activity of brain and nervous-system neurons

These bodily adaptations change a person's behavior. The levels of alcohol dehydrogenase and aldehyde dehydrogenase in the liver increase in response to long-term alcohol exposure. This means that the body becomes more efficient at eliminating the high levels of alcohol in the blood. However, it also means that the person must drink more alcohol to experience the same effects as before, which leads to more drinking and contributes to addiction.

The normal chemical and electrical functions of nerve cells increase to compensate for the inhibitory effects of alcohol exposure. This increased nerve activity helps people to function normally with higher BAC; however, it also makes them irritable when they are not drinking. Furthermore, the increased nerve activity may make them crave alcohol. Most certainly, the increased nerve activity contributes to hallucinations and convulsions (e.g. delirium tremens) when alcohol is withdrawn, and makes it difficult to overcome alcohol abuse and dependence.