Generalized anxiety disorder is an anxiety disorder that is characterized by excessive, uncontrollable and often irrational worry about everyday things, which is disproportionate to the actual source of worry.

This excessive worry often interferes with daily functioning, as individuals suffering Generalized Anxiety Disorder typically catastrophise, anticipate disaster, and are overly concerned about everyday matters such as health issues, money, family problems, or work difficulties. They often exhibit a variety of physical symptoms, including fatigue, headaches, muscle tension, muscle aches, difficulty swallowing, trembling, twitching, irritability, sweating, and hot flashes. These symptoms must be consistent and on-going, persisting at least 6 months, for a formal diagnosis of Generalized Anxiety Disorder to be introduced. Approximately 6.8 million American adults experience Generalized Anxiety Disorder, affecting about twice as many women as men.

According to the DSM IV, the following criteria must be met for a person to be diagnosed with Generalized Anxiety Disorder.

1. Excessive anxiety and worry (apprehensive expectation), occurring more days than not for at least six months, about a number of events or activities (such as work or school performance).
2. The person finds it difficult to control the worry.
3. The anxiety and worry are associated with three (or more) of the following six symptoms (with at least some symptoms present for more days than not for the past 6 months). Note: Only one item is required in children.

   1. restlessness or feeling keyed up or on edge
   2. being easily fatigued
   3. irritability
   4. muscle tension
   5. difficulty falling or staying asleep, or restless unsatisfying sleep
   6. difficulty concentrating or the mind going blank
4. The focus of the anxiety and worry is not confined to features of an Axis I disorder, e.g., the anxiety or worry is not about having a panic attack (as in panic disorder), being embarrassed in public (as in social phobia), being contaminated (as in obsessive-compulsive disorder), being away from home or close relatives (as in Separation Anxiety Disorder), gaining weight (as in anorexia nervosa), having multiple physical complaints (as in somatization disorder), or having a serious illness (as in hypochondria), and the anxiety and worry do not occur exclusively during post-traumatic stress disorder.
5. The anxiety, worry, or physical symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
6. The disturbance is not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition and does not occur exclusively during a Mood Disorder, a Psychotic Disorder, or a Pervasive Developmental Disorder.

Some research suggests that Generalized Anxiety Disorder may run in families, and it may also grow worse during stress. Generalized Anxiety Disorder usually begins at an earlier age and symptoms may manifest themselves more slowly than in most other anxiety disorders. Some people with Generalized Anxiety Disorder report onset in early adulthood, usually in response to a life stressor. Once Generalized Anxiety Disorder develops, it is chronic.