Snoring itself isn’t a health hazard. Though it raises a racket, air is still getting into the lungs. But loud snoring can be a sign of sleep apnea, a serious condition in which breathing repeatedly becomes very shallow or stops altogether during sleep. In obstructive sleep apnea, tissues in the throat – often the soft palate and uvula – not only vibrate, but periodically block the airway completely. (In central sleep apnea, the central nervous system “forgets” to tell the body to breathe.) But not all snorers have sleep apnea; the diagnosis requires overnight monitoring in a sleep clinic.
(Source: Harvard Health Letter May 2002)