An excessive, unrealistic fear of a specific object, situation, or activity that causes a person to avoid that object, situation, or activity.

Unlike generalized anxiety, phobias involve specific, identifiable but usually irrational fears. Phobias are common occurrences among a large segment of the population. People with phobias recognize that their fears are irrational, yet avoid the source to spare themselves of the resultinganxiety. Phobias are classified as disorders only when they interfere substantially with a person's daily life.

Psychologists have identified three categories of phobic disorders. The first, simple phobia, is defined in Diagnostic and Statistical Manual of Mental Disorders as a persistent, irrational fear of, and compelling desire to avoid, an object or a situation other than being alone, or in public...