A person is considered drunk or intoxicated when he or she suffers from behavioral or psychological changes such as inappropriate sexual or aggressive behavior, mood swings, impaired judgment, impaired social or occupational functioning that develop during or shortly after alcohol consumption. Below is a list of common symptoms of intoxication:

• Slurred speech
• Poor coordination
• Cannot walk straight
• Rapid eye movement
• Impaired attention or memory
• Stupor or coma

The best way to tell if someone is intoxicated is through the amount of alcohol in his or her blood. The blood-alcohol concentration (BAC) is expressed as a percentage. Here's an example:

A BAC of 0.05% means that out of 10,000 blood component parts, five parts are alcohol.

BAC	Effects on the Drinker
.02	Relaxed feeling, less self-conscious
.05	Increased relaxed feelings, less alert, less coordinated
.08	Impaired coordination and judgement
.10	Typically show embarrassing behavior, moody, slow reaction time
.15	Drastically impaired coordination and balance
.30	Possible loss of consciousness
.40	Probable loss of consciousness, death is a possibility
.50	Loss of consciousness, may stop breating, death is a strong possibility.

The U.S Department of Transportation asked states to set 0.08% as the blood alcohol concentration at which a person will be cited for drunk driving. The level of 0.08% can be typically reached by a 150lb man who consumed 3 mixed drinks and even less for women. Check with your state for its exact percentage.

If these symptoms are noticeable on a regular basis, it may be wise to view the Questions to Ask page to learn about the warning signs of alcoholism.

US Department of Health and Human Services
10th Special Report to the U.S. Congress on Alcohol and Health, June 2000.