Alcohol use produces a wide spectrum of short- and long-term effects on nearly every organ system in the body. In the short term, alcohol acts as a central nervous system depressant, causing impaired judgment, slowed reaction time, poor coordination, slurred speech, and altered mood, while higher doses can lead to respiratory depression, blackout, vomiting, hypoglycemia, and alcohol poisoning, which may be fatal. With repeated or prolonged use, alcohol exerts cumulative toxic effects, particularly on the liver, leading to fatty liver disease, alcoholic hepatitis, fibrosis, and cirrhosis. Long-term alcohol use is also associated with cardiomyopathy, hypertension, stroke, pancreatitis, gastrointestinal bleeding, immune suppression, nutritional deficiencies (especially thiamine), and cognitive impairment. Chronic exposure increases the risk of several cancers, including those of the liver, esophagus, breast, and colon, and can result in alcohol use disorder, a chronic relapsing brain disease characterized by compulsive drinking, tolerance, and withdrawal symptoms upon cessation.