Generalized anxiety disorder (GAD) is an anxiety disorder characterized by excessive, uncontrollable and often irrational worry, that is, apprehensive expectation about events or activities. This excessive worry often interferes with daily functioning, as individuals with GAD typically anticipate disaster, and are overly concerned about everyday matters such as health issues, money, death, family problems, friendship problems, interpersonal relationship problems, or work difficulties. Individuals often exhibit a variety of physical symptoms, including fatigue, fidgeting, headaches, nausea, numbness in hands and feet, muscle tension, muscle aches, difficulty swallowing, excessive stomach acid buildup, stomach pain, vomiting, diarrhea, bouts of breathing difficulty, difficulty concentrating,  trembling, twitching, irritability, agitation, sweating, restlessness, insomnia, hot flashes, rashes, and inability to fully control the anxiety (ICD-10). These symptoms must be consistent and ongoing, persisting at least six months, for a formal diagnosis of GAD.