Differential diagnosis of anxiety disorders.

The literature comparing panic disorder with natural fear, hypoglycemia, hyperthyroidism, pheochromocytoma, the hyperventilation syndrome, the mitral valve prolapse syndrome and partial complex seizures is briefly reviewed. Some features of each of these syndromes may clinically resemble panic disorder. It is concluded that: a) patients with panic disorder should be medically evaluated. b) the diagnosis of panic disorder should be based on a broad system, rather than on symptoms alone. c) diagnostic systems should include a category for "organic anxiety syndromes".