Phobia (恐惧症) is intense and continuous fear of a specific object, situation, or activity. Because of this intense and constant fear, the phobic person often leads a restricted life. The anxiety is typically out of proportion (不相称的) to the real situation, and the victim is fully aware that the fear is irrational.Phobic anxiety is different from other forms of anxiety only in that it occurs in relation to a certain object or situation. This anxiety is characterized by symptoms (症状) such as a rapid heartbeat, stomach disorders, choking feelings, sweating, and faintness. Some phobic people are able to face bravely their fears. More commonly, however, they avoid the situation or object that causes the fear.There are three major types of phobias. Simple phobias are fears of specific (具体的) objects or situations such as animals, closed spaces, and heights. The simple phobias, especially the fear of animals, may begin in childhood and continue into adulthood. The second type, agoraphobia, is fear of open, public places and situations (such as public vehicles and crowded shopping centers) from which escape is difficult; agoraphobia tend increasingly to avoid more situations until eventually they become housebound (闭门不出的). Social phobias, the third type, are fears of appearing stupid or shameful in social situations.Although agoraphobia is more often seen in treatment than the other types of phobias, it is not believed to be as common as simple phobias. Taken together, the phobias are believed to affect 5 to 10 persons in 100. Agoraphobia and simple phobias are more commonly diagnosed in women than in men; the distribution for social phobias is not known. Agoraphobias, social phobias, and animal phobias tend to run in families.Behavioral techniques have proved successful in treating phobias, especially simple and social phobias. One technique involves gradually confronting the phobic person with situations or objects that are increasingly close to the feared ones. Exposure therapy, another behavioral method, has recently been shown more effective. In this technique, phobic people are repeatedly exposed to the feared situation or object so that they can see that no harm comes to them; the fear gradually fades.