Anxiety is a vague feeling of dread, apprehension or fear. This is the body's normal reaction to threatening or dangerous situations. A certain amount of anxiety is useful, as it stimulates us to act.

However, in some individuals, excess and ongoing anxiety can interfere with normal functioning. Disorders characterized by extreme anxiety include neurosis, phobias and posttraumatic stress disorder.

In some cases, anxiety disorders can be treated by counseling and psychotherapy, or by avoiding the situations that cause excess panic. Drugs can also be used to reduce anxiety, by interfering with brain chemicals that signal stress and anxiety (for example, see beta blockers).