Generalize anxiety disorder (GAD) 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 GAD typically catastrophise, anticipate disaster, and are overly concerned about everyday matters such as health issues, money, family problems, friend 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, insomnia, and hot flashes. These symptoms must be consistent and on-going, persisting at least 6 months, for a formal diagnosis of GAD to be introduced. Approximately 6.8 million American adults experience GAD, affecting about twice as many women as men.