http://www.psychologytoday.com/conditions/agoraphobiaAgoraphobia
Leaving home can be a reason to panic for some. Agoraphobia refers to a fear of any place where escape may be difficult, including large open spaces or crowds, as well as various means of travel.
Translated from Greek as "fear of the marketplace," agoraphobia involves intense fear and anxiety of any place or situation where escape might be difficult. Agoraphobics may avoid situations such as being alone outside of the home; traveling in a car, bus, or airplane; being in a crowded area; or being on a bridge or in an elevator.
Endurance of such situations can put a person with agoraphobia under great stress, and a panic attack may result. Such high discomfort and stress may require another person's company in such situations.
Agoraphobia often accompanies another anxiety disorder, such as panic disorder or a specific phobia. If agoraphobia occurs with panic disorder, the onset is usually during the 20s; women are affected more often than men. Approximately 1.8 million American adults age 18 and over (about 0.8 percent of people in this age group in a given year) have agoraphobia without a history of panic disorder.
In panic disorder, panic attacks recur and the person develops an intense apprehension of having another attack. This fear—called anticipatory anxiety or fear of fear—can be present most of the time and seriously interfere with the person's life even when a panic attack is not in progress.
Agoraphobia affects about a third of all people with panic disorder. Typically, people with agoraphobia restrict themselves to a "zone of safety" that may include only the home or the immediate neighborhood. Any movement beyond the edges of this zone creates mounting anxiety. Even when they restrict themselves to "safe" situations, most people with agoraphobia continue to have panic attacks at least a few times a month.
People with agoraphobia can be seriously disabled by their condition. Some are unable to work, and they may need to rely heavily on other family members, who must do the shopping and household errands, as well as accompany the affected person on rare excursions outside the "safety zone." People with this disorder may become housebound for years, with resulting impairment of social and interpersonal relationships. Thus the person with agoraphobia typically leads a life of extreme dependency as well as great discomfort.
