Addiction is a disease. It occurs when a person consumes or uses a substance such as drugs, alcohol or nicotine, or when a person engages in a behavior such as shopping, sex, or gambling for pleasure but the ongoing use/behavior ultimately becomes compulsive. The use/behavior of an addict interferes with day-to-day life, relationships and normal responsibilities. People who have an addiction are often not aware that their behavior is out of control or that they are causing problems for themselves and those who care about them. To learn more about the different types of addictions, please choose one of the topics below.