In treating the symptomatology of patients who are chronically ill, it is likely that the physician will encounter a significant number of patients who have sleep disorders. This article has described an approach for the assessment, differential diagnosis, and clinical management of the most prevalent sleep disorders, which are often chronic in nature and have significant psychosocial or medical consequences for the patient and his or her family. We have emphasized the importance for the physician to complement his general medical and diagnostic skills by taking a careful sleep history from the patient (and, in some instances from the bed partner or caretakers). There is no justification for the physician to routinely request costly sleep laboratory hypnopolygraphic evaluations to screen patients with sleep disorders. However, in those instances where the sleep history is highly suggestive of sleep apnea, a sleep laboratory evaluation is indicated. By incorporating the use of the sleep history in the general evaluation of patients with sleep disorders, the physician is better able to develop rational pharmacologic and non-pharmacologic approaches to managing these patients, including the judicious use of medication as an adjunctive treatment.