Obstructive sleep disorders range from simple snoring to severe obstructive sleep apnea.

The distinction is made using the apnea-hypopnea index obtained through a "polysomnography" test, which records various parameters such as snoring, apnea-hypopneas, sleep stage, body position, oxygen saturation during sleep, and according to day-time symptoms.

Polysomnography is a multi-parameter study of sleep and the gold standard diagnostic tool in sleep medicine