Panic disorder is is an anxiety disorder characterized by unexpected and repeated episodes of intense fear accompanied by physical symptoms that may include chest pain, heart palpitations, shortness of breath, dizziness, or abdominal distress. These episodes occur “out of the blue,” not in conjunction with a known fear or stressor. These “panic attacks,” which are the hallmark of panic disorder, are believed to occur when the brain’s normal mechanism for reacting to a threat (the “fightor-flight” response), becomes inappropriately aroused.

Anxiety disorders are illnesses related to this fear response being activated more strongly than necessary or when not necessary at all. Most people with panic disorder feel anxious about having panic attacks and avoid situations in which they believe these attacks are likely to occur. Anxiety about another attack and the avoidance it causes can lead to disability.

About 2.7% of the U.S. population, or approximately 2.4 million people, has panic disorder in a given year. Women are twice as likely to develop the disorder as men. Panic disorder usually begins in young adulthood; nearly half of those affected develop the condition before they turn 24. While people of all races and social classes can develop panic disorder, there are differences in how symptoms are expressed.