Generalized anxiety disorder (GAD) is an anxiety disorder marked by chronic, exaggerated worrying and anxiety about everyday life. Everyone worries at times. But people with GAD can never relax and usually anticipate the worst. They often worry excessively about health, family, work, or money. The worry is so severe that it interferes with their ability to live their lives. The anxiety can also progress to the point where people "worry about worrying." GAD usually starts in childhood or adolescence. But it can also start in early adulthood.

The exact cause of GAD is unknown. Researchers believe it is caused by a combination of genetic, environmental, developmental, and psychological factors.