Ingestion of alcoholic beverages to the point of it causing damage to the drinker in social, physical, mental, or economic areas is the typical definition of alcoholism. Yet other sources cite alcoholism as a disease (this is widely debated - many claim that it is because alcoholics would, if possible, change their addictive behavior, and that their inability to quit is because they have lost control of their drinking.), an addiction, a characteristic of a deeper psychological or physical disorder, a learned response to a crisis, or a combination of these. The actual definition of alcoholism will be based on the person who is defining it. Epidemiologists will define alcoholism in terms of the population's identification, and those defining it legally will stress that alcoholics are dangerous to other people because they drink.

When defining or diagnosing alcoholism, it is important to remember that behavioral signs are more reliable than physiological or pharmacological signs. Also, when a counselor defines alcoholism, he/or she typically includes one or more of the following:

1. The consumption of alcohol over a long period of time
2. Ethanol addiction evidence
3. Irregular and persistent drinking behaviors marked by lack of self-control
4. Damage to health, social, and/or economic status (e.g. withdrawal from friends/family or loss of job)

All four of these areas of alcoholism are defined by excessive drinkers who depend on alcohol to the extent that there is a marked mental disruption in their mental and physical functioning.