Gambling involves risking money or something of value on an event based on chance, such as the roll of a dice or the outcome of a horse race. It also includes activities like buying scratch-off lottery tickets, playing the slot machines in casinos or placing bets with friends. Gambling can be a fun and harmless hobby, but for some people, gambling becomes a problem. It can affect their physical and mental health, ruin relationships, cause financial difficulties, lead to homelessness and get them into legal trouble. Problem gambling can also cause a person to isolate themselves and become isolated from family, friends and work.

The symptoms of gambling disorder can start in early adolescence or later in adulthood and may occur on both a short- and long-term basis. The condition tends to run in families and can be aggravated by factors such as trauma and social inequality, especially for women. People with unhealthy gambling habits can experience a variety of psychological and behavioral problems, including anxiety and depression. In some cases, a person with an unhealthy gambling habit develops a tolerance to the activity, which means that they have to spend more money on gambling to feel the same high as before.

Until recently, the psychiatric community viewed pathological gambling as an impulse-control disorder, like kleptomania or pyromania (fire-starting). However, in what is widely regarded as a landmark decision, the American Psychiatric Association has moved this type of gambling disorder into the chapter on addictions in its Diagnostic and Statistical Manual of Mental Disorders, which informs psychologists about how to treat patients.