Snoring occurs due to the vibration of tissues within the throat when the airway muscles relax during sleep.Most commonly, this is due to turbulent airflow affecting the soft palate, uvula, or base of the tongue.Difficulty breathing through the nose may predispose toward mouth breathing and snoring.If the mouth opens at night, the lower jaw and tongue may shift backwards, affecting airflow through the throat.When snoring is loud and accompanied by daytime sleepiness and a lack of feeling refreshed in the morning, it may be a sign of obstructive sleep apnea.