1. Prevents snoring
If your partner snores or you are the one who snores loudly all night, sleeping on the left side may be the solution to their mutual happiness. Before you get too excited this does not alleviate all the causes of snoring. But it does keep your tongue and throat in a more neutral position and leaves your airways freer.
While we sleep the mouth, the throat and the tongue relax. Sleeping on your back is the worst thing for those who snore, because those tissues relax upside down and can partially block the airway. Snoring is caused by inhaling air through a narrow space.