Panic disorder is a real illness that can be successfully treated. It is characterized by sudden attacks of terror, usually accompanied by a pounding heart, sweatiness, weakness, faintness, or dizziness. During these attacks, people with panic disorder may flush or feel chilled, their hands may tingle or feel numb, and they may experience nausea, chest pain, or smothering sensations. Panic attacks usually produce a sense of unreality, a fear of impending doom, or a fear of losing control. People who have full-blown, repeated panic attacks can become very disabled by their condition, avoiding leaving home, and should seek treatment before they become debilitated.