An Overview on Sleep Medicine.

Sleep plays an important role in homeostasis, brain plasticity, clearance of neurotoxins, cognition, memory, concentration, performance, and the regulation of the temperature, endocrine and immunological systems. Insufficient, disorganized, and poor-quality sleep impacts performance, cognition, and safety, carries social and economic consequences and predisposes to obesity, excessive daytime sleepiness, fatigue, arterial hypertension, diabetes, stroke, coronary arterial disease, Alzheimer's disease, depression, and anxiety. Consequently, the search of sleeping well and sufficiently aims to be happy, healthy, and being productive at work, social and family levels. Therefore, one of the fundamental pillars of health is sleeping an adequate number of hours, follow regular sleep-wake habits and identify sleep disorders. There is a wide variety of sleep disorders that may impact the patient quality of life such as obstructive sleep apnea, chronic insomnia, narcolepsy, delayed sleep-wake phase disorder and Kleine-Levin syndrome. The need to study sleep and its disturbances made the appearance of Sleep Medicine. This is a relatively new discipline that was born in the second half of the twentieth century and aims to promote good sleep hygiene and detect and treat those sleep disorders impairing the subject quality of life. Moreover, the field has expanded to fields such as the evaluation of pediatrics, women, aging, shift work, sports, forensic aspects, and its socioeconomic impact.