Sleep medicine is a subspecialty devoted to the diagnosis and therapy of sleep disturbances and disorders. Disordered and disturbed sleep are associated with up to 1/3 of fatal motor vehicle fatalities as daytime sleepiness is a common symptom. Abnormal sleep can be associated as well as impact chronic medical conditions such as hypertension, obesity and mood disorders. Chronic obstructive sleep apnea, sleep deprivation, insomnias, narcolepsy, restless leg syndrome and hypersomnias may be treatable. Sleep Medicine is a multidisciplinary specialty and physicians who seek certification may be internists, pulmonologists, pediatricians, neurologists, or otolaryngologists.