Generalized anxiety disorder: Abbreviated GAD. A condition characterized by 6 months or more of chronic, exaggerated worry and tension that is unfounded or much more severe than the normal anxiety most people experience. People with GAD usually expect the worst. They worry excessively about money, health, family, or work, even when there are no signs of trouble. They are unable to relax and often suffer from insomnia. Sometimes the source of the worry is hard to pinpoint. Simply the thought of getting through the day provokes anxiety. Many people with GAD also have physical symptoms, such as fatigue, trembling, muscle tension, headaches, irritability or hot flashes. People with GAD may feel lightheaded or out of breath. They also may feel nauseated or have to go to the bathroom frequently. Nearly 3% of the adult US population age 18 to 54 has GAD during the course of a given year. GAD most often strikes in childhood or adolescence, but can also begin in adulthood. It affects women more often than men, may run in families, and may also grow worse with stress. GAD often coexists with depression, substance abuse, and other anxiety disorders. Irritable bowel syndrome, often accompanies GAD. Treatment for GAD includes medications and cognitive-behavioral therapy.