I’ve never found this position comfortable to sleep in, but many people do, and unfortunately, it isn’t ideal for the body. Why? Sleeping face-down forces both the neck and the jaw to be in an unnatural position for hours at a time, leading to muscle pain and even damage. A good way to remedy this is to stay in the face-down position until you feel that you are just about to fall asleep, and then to turn over onto your side. If you are someone who naturally moves back to the face-down position in your sleep, try having a pillow on your side.