Intoxication is a temporary and reversible condition that affects the central nervous system after a person ingests certain substances, such as alcohol or drugs. Intoxication affects judgment, the ability to think clearly, and behaviour.

People who are intoxicated may become belligerent, aggressive (including sexually aggressive), or quiet and may not be able to perform work, family, or social responsibilities. Physical signs of intoxication include slurred speech, clumsiness, and problems with memory and attention. Some people who are intoxicated pass out. Severe intoxication can be a serious threat to health, and it can even cause death.