The word "phobia" is a term that refers to a group of symptoms brought on by feared objects or situations.
A phobia is a persistent, irrational fear that causes a person to feel intense anxiety.
People develop phobias about many things like darkness, social situations, spiders, or blood. Agoraphobia, one of the most common phobias, involves the fear of open places. A person with agoraphobia feels anxious in places where it would be hard to escape, like being in a crowd, standing in line, being on a bridge or traveling in a car. In extreme cases, they are so immobilized by fear that they become a prisoner in their own home.
Phobias are the most common form of anxiety disorders, which affect people of all ages, at all income levels and in all geographic locations, according to a study by American the National Institute of Mental Health (NIMH), between 5.1 and 21.5 percent of Americans suffer form Phobias. Broken down by age and gender, the NIMH study found phobias were the most common psychiatric illness among women in all age groups and the second most common illness among men older than 25.
In some people, the response to a phobia can be fairly mild. For example, a person who has a phobia about flying might simply avoid airplanes. In other people, the phobia causes, or arises from, full-blown panic attacks with symptoms such as shortness of breath, sweating, irregular heartbeats and the shakes. Just why a person develops a particular phobia is not always clear. There appear to be both biological and psychological reasons. Psychologists classify phobias with other anxiety-caused problems and theorize they are a response to separation or loss. Heredity appears to play a role, and so does brain chemistry.