The place of polysomnography in internal medicine.

As the medical community and the general public have become more aware of the relationships among snoring, excessive daytime sleepiness, cardiovascular and metabolic disease, and obstructive sleep apnoea (OSA), physicians are seeing an increasing number of patients with these problems. In internal medicine high prevalences of sleep related-breathing disorders have been reported, with a high likelihood to develop chronic complications. The coincidence of OSA with alteration of one or more systems produces mutual potentiation of their negative effects. Polysomnography plays a prominent role in the evaluation of sleep disorders and diagnosing OSA, since the disorder cannot be correctly suspected on the basis of interview and physical examination alone. Increased awareness of the atypical presentation of OSA in different patient populations is warranted. Appropriate treatment can prevent burden to the patients and development of serious complications, including sudden death in sleep. These interactions illustrate the multidisciplinary nature of sleep medicine, above all in the field of diagnostics and therapy.