Alcohol intoxication (also known as drunkenness or inebriation) is a physiological state that occurs when a person has a high level of ethanol (alcohol) in his or her blood.

Common symptoms of alcohol intoxication include slurred speech, euphoria, impaired balance, loss of muscle coordination (ataxia), flushed face, vomiting, reddened eyes, reduced inhibition, and erratic behavior. In severe cases, it can cause coma or death.

Toxicologists use the term “alcohol intoxication” to discriminate between alcohol and other toxins.

Acute alcohol intoxication results from a very high level of alcohol in the blood. This term is used by health care providers, often in emergencies.

Alcohol is metabolized by a normal liver at the rate of about one ounce (one "highball", a normal beer, a regular sized glass of wine) every 90 minutes. An "abnormal" liver with conditions such as hepatitis, cirrhosis, gall bladder disease, and cancer will have a slower rate of metabolism.

Ethanol is metabolised to acetaldehyde by alcohol dehydrogenase (ADH), which is found in many tissues, including the gastric mucosa. Acetaldehyde is metabolised to acetate by acetaldehyde dehydrogenase (ALDH), which is predominantly found in liver mitochondria. Acetate is used by the muscle cells to produce acetyl-CoA using the enzyme acetyl-CoA synthetase, and the acetyl-CoA is then used in the citric acid cycle. It takes roughly 90 minutes for a healthy liver to metabolize a single ounce, approximately one hour per standard unit.