I snored for years, and on investigation, it was found I suffered from a condistion called sleep apnea - where the sufferer stops breathing in their sleep for a few seconds. The condition is dangerous because the heart speeds up in an effort to re-start the breathing when it stops, sometimes literally hundreds of times in a night, and a strain is placed on the heart's normal function.
The 'cure' was to have my tonsils removed - not pleasant, but the benefits in terms of mine (and my wife's!) sleep has made it worthwhile - I don't snore at all anymore!