Although anxiety is often accompanied by physical symptoms, such as a racing heart or knots in your stomach, what differentiates a panic attack from other anxiety symptoms is the intensity and duration of the symptoms. Panic attacks typically reach their peak level of intensity in 10 minutes or less and then begin to subside. Due to the intensity of the symptoms and their tendency to mimic those of heart disease, thyroid problems, breathing disorders, and other illnesses, people with panic disorder often make many visits to emergency rooms or doctors' offices, convinced they have a life-threatening issue.
Biological causes may include obsessive compulsive disorder, Postural Orthostatic Tachycardia Syndrome, post traumatic stress disorder, hypoglycemia, hyperthyroidism, Wilson's disease, mitral valve prolapse, pheochromocytoma, and inner ear disturbances (labyrinthitis). Dysregulation of the norepinephrine system in the locus ceruleus, an area of the brain stem, has been linked to panic attacks.
People with generalized anxiety disorder (GAD) display excessive anxiety or worry, most days for at least 6 months, about a number of things such as personal health, work, social interactions, and everyday routine life circumstances. The fear and anxiety can cause significant problems in areas of their life, such as social interactions, school, and work.