Common endocrine disorders often present with psychiatric symptoms and may be mistaken for primary psychiatric disorders. Dysregulation of the following endocrine systems commonly affects behavior: the adrenocorticoid system, the thyroid system, the parathyroid system, the pancreas and regulation of glucose, and the reproductive system. Symptoms of depression and anxiety are common across the spectrum of endocrine disorders and more severe cases may include psychotic features. Clinicians are often faced with the challenge of identifying an underlying endocrine etiology for behavioral changes based on relatively nonspecific symptoms. A general understanding of the signs and symptoms associated with elevated or decreased hormone levels can assist in the differential diagnosis and ultimately increase the likelihood that a patient receives appropriate treatment. Accurate diagnosis can be especially critical in acute behavioral emergencies.