**Abstract**

Over recent years, the importance of sleep physiology and pathology has been better understood in terms of correct diagnosis, treatment, prognosis and innovative research of diseases. Sleep disorders are often confused with clinical symptoms of adult and pediatric medical conditions. In medicine, electrophysiological signal recording methods are very important for establishing a correct diagnosis especially in neurological sciences. Polysomnography (PSG) is a golden standard diagnostic method that records electrophysiological signals used for sleep physiology and diseases. When the medical disciplines and diseases that make use of this diagnostic method are considered, its significance becomes clearer. For example, medical disciplines benefiting from PSG are as follows: "Clinical Physiology, Neurology, Ear Nose and Throat, Dentistry, Psychiatry, Pulmonology, Cardiology, Pediatric Neurology, Pediatric Cardiology, Internal Medicine, Neurosurgery, Endocrinology, etc." The patient groups diagnosed with PSG are as follows: "Sleep Disordered Breathing (Central Sleep Apnea Syndrome, Obstructive Sleep Apnea Syndrome), Obesity, Morbid Obesity, REM Behavior Disorder, Restless Leg Syndrome, Rhythm Disorders, Epileptic Disorders, Insomnia, Insomnia and Headache, Hypersomnia, Narcolepsy, Secondary Hypertension, etc." Interpretation and understanding electrophysiological signals correctly show us interactions of body systems with sleep physiology and integrated therapeutic approaches to sleep disorders. In conclusion; new approaches to sleep pathophysiology depend on a better understanding and further advancement of polysomnography.

**Keywords:** electrophysiology, awake, sleep, mechanism, PSG, correct diagnosis, innovation
