Overview of Alcohol Consumption

  People drink to socialize, celebrate, and relax. Alcohol often strongly affects people – and throughout history, we’ve struggled to understand and manage alcohol’s power. Why does alcohol cause us to act and feel differently? How much is too much? Why do some people become addicted while others do not?

  At the National Institute on Alcohol Abuse and Alcoholism (NIAAA), the answers to these and many other questions about alcohol are continuously researched. Here’s what the NIAAA knows:

  Alcohol’s effects vary from person to person, depending on a variety of factors, including:

  • How much you drink
  • How often do you drink
  • Your age
  • Your health status
  • Your family history

  While drinking alcohol is not necessarily a problem – drinking too much can cause many consequences and increase your risk for various issues.

Consequences of drinking too much

  Alcohol enters your bloodstream as soon as you take your first sip. Alcohol’s immediate effects can appear within about 10 minutes. As you drink, you increase your blood alcohol concentration (BAC) level, which is the amount of alcohol in your bloodstream. The higher your BAC, the more impaired you become by alcohol’s effects. These effects can include:

  • Reduced inhibitions
  • Slurred speech
  • Motor impairment
  • Confusion
  • Memory problems
  • Concentration problems
  • Coma
  • Breathing problems
  • Death

  Other risks of drinking can include:

  • Car crashes and other accidents
  • Risky behavior
  • Violent behavior
  • Suicide and homicide

  People who drink too much over a long period may experience alcohol’s longer-term effects, which can include:

  •      Alcohol use disorder
  •      Health problems
  •      Increased risk for certain cancers

  In addition, long-term alcohol use disorder may result in Wernicke-Korsakoff syndrome, a brain disorder due to thiamine (vitamin B1) deficiency. Lack of vitamin B1 is common in people with alcohol use disorder; for more information on Alcoholism, visit

Alcohol’s Effects on the Body

  Drinking too much – on a single occasion or over time – can severely affect your health. Here’s how alcohol can affect your body:


  Alcohol interferes with the brain’s communication pathways and can affect the way the brain looks and works. These disruptions can change mood and behavior, making it harder to think clearly and move with coordination.


  Drinking a lot over a long time or too much on a single occasion can damage the heart, causing problems including:

  • Cardiomyopathy – Stretching and drooping of the heart muscle
  • Arrhythmias – Irregular heartbeat
  • Stroke
  • High blood pressure

  Research also shows that drinking moderate alcohol may protect healthy adults from developing coronary heart disease.


  Heavy drinking takes a toll on the liver and can lead to a variety of problems and liver inflammations, including:

  • Steatosis, or fatty liver
  • Alcoholic hepatitis
  • Fibrosis
  • Cirrhosis


  Alcohol causes the pancreas to produce toxic substances that can eventually lead to pancreatitis, a dangerous inflammation, and swelling of the blood vessels in the pancreas that prevents proper digestion.


  Drinking too much alcohol can increase your risk of developing certain cancers, including cancers of the:

  • Mouth
  • Esophagus
  • Throat
  • Liver
  • Breast

Immune System:

  Drinking too much can weaken your immune system, making your body a much easier target for disease. Chronic drinkers are more liable to contract diseases like pneumonia and tuberculosis than people who do not drink too much. Drinking a lot on a single occasion slows your body’s ability to ward off infections – even up to 24 hours after getting drunk.

Alcohol Use Disorder (AUD)

  Problem drinking that becomes severe is given the medical diagnosis of “alcohol use disorder” or AUD. Approximately 7.2 percent, or 17 million adults in the United States ages 18 and older, had an AUD in 2012. This percentage includes 11.2 million men and 5.7 million women. Adolescents can also be diagnosed with AUD; in 2012, an estimated 855,000 adolescents ages 12–17 had an AUD.

  Individuals must meet specific criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM) to be diagnosed with AUD. Under DSM–5, the current version of the DSM, anyone meeting any two of the 11 criteria during the same 12-month period receives a diagnosis of AUD. The severity of an AUD—mild, moderate, or severe—is based on the number of criteria met.

Here are some questions to assess whether you or a loved one may have an AUD. In the past year, have you: