There are many people who like to sleep on their stomachs because when the fetus is in the mother’s womb, the fetus sleeps with its body curled up against the mother. When the baby sleeps on its back, its side, belly, and stomach are pressed against the soft mattress, which is simulating the feeling of being in the mother’s arms. Therefore the fetus after birth also like to sleep on their backs, which is looking for a natural sense of security. When the habit after the wave, to the adult stage many people also like to sleep on their stomachs, but there are many hazards of sleeping on their stomachs. Sleeping on your back may fall asleep faster, but this posture does not allow the body to get deep relaxation, but also let the skin, muscles in a state of tension, after a long time will feel tired and uncomfortable. Many staff in the lunch break used to sleep on their stomachs, this posture will cause serious impact on the cervical spine, shoulders, neck muscles will be in a position for a long time, and become very stiff, over time will form cervical spondylosis.