Fear of of any place or situation where escape might be difficult or help unavailable in the event of developing sudden panic-like symptoms. Approximately 3.2 million American, have agoraphobia.Agoraphobia is defined as the abnormal fear of being helpless in a situation from which escape may be difficult or embarrassing. Those suffering from agoraphobia--an estimated 5 percent of the U.S. population—may avoid bridges, busy streets, and crowded stores. In extreme cases, patients may become so disabled that they refuse to leave their homes. Two-thirds of those who suffer from agoraphobia are women, and symptoms usually develop between late adolescence and the mid-30s. Most people suffering from agoraphobia develop the disorder after suffering from one or more spontaneous panic attacks. These attacks seem to occur randomly, making it impossible to predict what situation will trigger the next reaction. The unpredictability of the attacks trains a person to anticipate future attacks and avoid any situations that could trigger them.