Alcohol withdrawal is a condition that follows a reduction in al-cohol consumption or an abrupt cessation of drinking in alcohol-dependent individuals. In addition to significant distress, alcohol withdrawal is also associated with impairment of social, occu-pational and other areas of functioning. Uncomplicated cases of alcohol withdrawal are characterized by signs and symptoms of autonomic hyperactivity, and may include increased heart rate, increased blood pressure, hyperthermia, diaphoresis, tremor, nausea, vomiting, insomnia and anxiety. Onset of symptoms of uncomplicated alcohol withdrawal usually occurs between 4 and 12 hours following the last drink. Symptom severity tends to peak around the second day, usually subsiding by the fourth or fifth day of abstinence. After this period, less severe anxiety, insomnia and autonomic symptoms may persist for a few weeks, with some individuals experiencing a protracted alcohol-withdrawal syn-drome up to 5 or 6 months after cessation of drinking. A small but significant number of alcohol-dependent individuals (10%) can experience complicated alcohol-withdrawal episodes. Alcohol-withdrawal delirium (also known as delirium tremens) can occur in 5% of the cases, usually between 36 and 72 hours following alcohol cessation. In addition to signs of autonomic hyperactivity, this condition is characterized by illusions, auditory, visual, or tactile hallucinations, psychomotor agitation, fluctuating cloudi-ness of consciousness and disorientation. Grand-mal seizures associated with alcohol-withdrawal occur in 3 to 5% of the cases, typically within the first 48 hours following reduction or cessation of drinking. In both instances of complicated alcohol withdrawal, lack or delay in instituting proper treatment is associated with an increased mortality rate. Prior history of delirium tremens and/or alcohol-withdrawal seizures, older age, poor nutritional status, comorbid medical conditions and history of high tolerance to al-cohol are predictors of increased severity of alcohol withdrawal.