The key features of generalized anxiety disorder are persistent and excessive anxiety and worry about various domains, including work and school performance that the individual finds difficult to control. In addition, the individual experiences physical symptoms, including restlessness or feeling keyed up or on edge; being easily fatigued; difficulty concentrating or mind going blank; irritability, muscle tension; and sleep disturbance.*

*Diagnostic and Statistical Manual of Mental Disorders: DSM-5. 5th ed. Washington, D.C.: American Psychiatric Association, 2013. 190. Print.