Once an individual has had a panic attack, for example, while driving, shopping in a crowded store, or riding in an elevator, he or she may develop irrational fears, called phobias, about these situations and begin to avoid them. Eventually, the avoidance and level of nervousness about the possibility of having another attack may reach the point at which the mere idea of engaging in the activities that preceded the first panic attack triggers future panic attacks, resulting in the person with panic disorder potentially being unable to drive or even step out of the house (agoraphobia). Thus, there are two types of panic disorder, panic disorder with or without agoraphobia. Like other mental health conditions, panic disorder can have a serious impact on a person's daily life unless the individual receives effective treatment.
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).