An Alcoholic is someone who drinks alcoholic beverages in such a way that it undermines their ability to function fully. In Alcoholic's Anonymous it is generally accepted that an alcoholic is someone who often, once they take the first drink, cannot control how much they drink. They may experience craving for alcohol when they attempt not to drink for periods of time. Many alcoholics also experience blackouts.
Some people believe someone is not an alcoholic unless they drink in the morning, have lost significantly in their lives, or have had multiple DUIs. However, alcoholism is a progressive disease, so many alcoholics do not show these signs until many years or decades into their illness.
Many people in recovery prefer to say they have an allergy to alcohol - when they drink, bad things happen - to help others who wonder if they are alcoholic not to generalize and assume that they cannot be alcoholic if they are successful in areas of their lives.
High-functioning alcoholics often have successful careers and appear to have health families, yet there are many signs pointing to a real problem. Family members may complain about their drinking; they may try to stop but are unable; they may get multiple DUIs; they may develop health problems such as pancreatitis, liver disease, cancer, heart disease, or ulcers.
Addiction Intervention specialist Earl Hightower says, "Normal drinkers don't walk around wondering if they are alcoholic," pointing to the fact that if someone is wondering if they have a problem with alcohol, they probably do.