These episodes are a serious health problem in the U.S. At least 20% of adult Americans, or about 60 million people, will suffer from panic at some point in their lives. About 1.7% of adult Americans, or about 3 million people, will have full-blown panic disorder at some time in their lives, women twice as often as men. The most common age at which people have their first panic attack (onset) is between 15 and 19 years of age. Panic attacks are significantly different from other types of anxiety, in that panic attacks are very sudden and often unexpected, appear to be unprovoked, and are often disabling.

People with panic disorder often worry about when the next attack will happen and actively try to prevent future attacks by avoiding places, situations, or behaviors they associate with panic attacks. Worry about panic attacks, and the effort spent trying to avoid attacks, cause significant problems in various areas of the person’s life, including the development of agoraphobia (see below).