There are several major types of anxiety disorders, each with its own characteristics.
People with generalized anxiety disorder have recurring fears or worries, such as about health or finances, and they often have a persistent sense that something bad is just about to happen. The reason for the intense feelings of anxiety may be difficult to identify. But the fears and worries are very real and often keep individuals from concentrating on daily tasks.
Panic disorder involves sudden, intense and unprovoked feelings of terror and dread. People who suffer from this disorder generally develop strong fears about when and where their next panic attack will occur, and they often restrict their activities as a result.
A related disorder involves phobias, or intense fears, about certain objects or situations. Specific phobias may involve things such as encountering certain animals or flying in airplanes, while social phobias involve fear of social settings or public places.
Obsessive-compulsive disorder is characterized by persistent, uncontrollable and unwanted feelings or thoughts (obsessions) and routines or rituals (compulsions) in which individuals engage to try to prevent or rid themselves of these thoughts. Examples of common compulsions include washing hands or cleaning house excessively for fear of germs, or checking work repeatedly for errors.
Someone who suffers severe physical or emotional trauma such as from a natural disaster or serious accident or crime may experience post-traumatic stress disorder. Thoughts, feelings and behavior patterns become seriously affected by reminders of the event, sometimes months or even years after the traumatic experience.
Symptoms such as extreme fear, shortness of breath, racing heartbeat, insomnia, nausea, trembling and dizziness are common in these anxiety disorders. Although they may begin at any time, anxiety disorders often surface in adolescence or early adulthood. There is some evidence that anxiety disorders run in families; genes as well as early learning experiences within families seem to make some people more likely than others to experience these disorders.