When a fear becomes so severe that it disrupts daily life, it is known as a phobia. A phobia is an excessive and irrational fear of an object or situation. Symptoms can include dizziness, a sense of unreality, or a fear of dying. More than 10% of the U.S. population suffers from some type of phobia, making it the most common mental disorder in the United States. You can find more information about phobias in the following articles.