Obstructive sleep apnea (OSA) is the most common sleep related breathing disorder where the person’s breathing stops and starts involuntarily. It occurs when throat muscles intermittently relax and block the airway and disrupt the breathing for 10 seconds or longer.

Brain detects this obstructed breathing and briefly awakens the person from sleep, so that the air passage may be cleared. This awakening is of such a short interval that the person doesn’t remember.