This document summarizes several types of anxiety disorders: panic disorder which involves sudden feelings of terror and physical symptoms; obsessive-compulsive disorder where disturbing thoughts cause rituals to be performed; post-traumatic stress disorder that can develop after a traumatic event; social anxiety disorder involving worry about social situations and being judged; specific phobias which are intense fears of specific objects or situations; and generalized anxiety disorder where a person worries excessively and is tense without provocation.