The symptoms of back pain when sleeping on a soft bed: 1. It may be because sleeping on a soft bed causes the normal physiological curvature of the waist to disappear, and can cause the waist to sink, which leads to excessive stretching of the fascia, ligaments and muscles of the waist, causing edema and spasm, and this situation is more obvious in the morning when the waist pain occurs, and there is obvious stiffness of the waist. 2. The area of contact with the bed surface is relatively large, especially the waist and back after a long period of large contact will affect the blood circulation of the skin and soft tissues, thus causing skin and soft tissue spasm and pain symptoms.