People's posture in sleep is not fixed. You feel that you keep a relatively fixed posture when you are asleep, but in fact, people's posture usually changes 20 to 60 times during the whole night's sleep. A healthier sleeping position has existed since ancient times, and that is "semi-lateral lying"! Sun Simiao, a famous health expert in the Tang Dynasty, said in his book "A Thousand Women's Children: Daolin Nourishes Nature": "Kneeling at your side is beneficial to people's strength and winning by fighting. "This kneeling posture emphasizes' half-side lying', which ensures the relaxation of the whole body, the smooth flow of qi and blood, and the access of viscera.

If it is more specific, lying on the right side is more scientific. When lying on the right side, the air intake of both lungs is the largest, and the oxygen needed by human body is transported by blood after gas exchange. In addition, the heart is located on the left side of the chest, and it is easy to be squeezed when lying on the left side, which is easy to increase the burden on the heart. Therefore, it is appropriate for normal people to lie on their side. It is worth noting that the pillow should not be too low when lying on your side, otherwise it will make your neck uncomfortable and easy to get stiff neck.