Anxiety is a normal human emotion that exists on a continuum from mild to severe. It is characterized by expectations not being met and the automatic rationalization of behaviors. Symptoms of anxiety include emotional, cognitive, and physical manifestations. Anxiety disorders affect around 25% of the population and have various theories around their causes including genetic, biological, cognitive-behavioral, and psychosocial factors. Common anxiety disorders include generalized anxiety disorder, panic disorder, phobic disorders, obsessive-compulsive disorder, post-traumatic stress disorder, and dissociative disorders. Treatment involves multidisciplinary interventions such as cognitive-behavioral therapy, medications, and observing nonverbal behaviors and relief patterns.