People with panic disorder suffer unexpected and repeated episodes of intense, overwhelming terror for no apparent reason (panic attacks).

Their fear may be accompanied by physical symptoms such as chest pain, heart palpitations, sweating, hot or cold flushes, trembling, dizziness, choking or smothering sensations and shortness of breath.

Panic attacks typically occur spontaneously, with no apparent trigger. They can occur at any time, even during sleep, and because they can not predict when a panic attack will seize them, many people live with the persistent worry that another attack could overcome them at any minute.

Most panic attacks last only a few minutes, but they occasionally go on for 10 minutes and, in rare cases, have been known to last for as long as an hour.

The symptoms of such panic attacks often mimic symptoms of a heart attack or other life-threatening medical conditions. Many people with panic disorder develop intense anxiety between episodes. It is not unusual for a person with panic disorder to develop phobias about places or situations where panic attacks have occurred, such as in supermarkets or other everyday situations.

Panic disorder can coexist with other disorders, most often depression and substance abuse. About 30% of people with panic disorder abuse alcohol and 17% abuse drugs, such as cocaine and marijuana, in unsuccessful attempts to reduce the distress caused by their condition.

Appropriate diagnosis and treatment of other disorders such as substance abuse or depression are important to successfully treat panic disorder.

The exact causes of panic disorder are unknown, but heredity and stressful life events may each be important.