Lying down the waist can not be completely close to the bed, considering the normal physiological curvature of the spine, there may be pathological factors such as lumbar disc herniation, lumbar muscle strain, rheumatoid spondylitis and other causes. 1. Normal physiological curvature of the spine: the human lumbar spine has a physiological structure of anterior convexity, when lying down, the lumbar region is usually not completely close to the bed, but there is a certain physiological curvature, if it is not accompanied by symptoms such as restricted movement and pain, usually no treatment is needed, and it is enough to observe. 2. Pathological factors (1) Herniated lumbar intervertebral disc: the bulging intervertebral disc can press on the peripheral nerves and blood vessels, causing local pain and numbness and other symptoms, usually through the spine sideways bending and rotating to relieve the pain, in the long run, the patient’s spine may be slightly deformed, so that the lumbar region can not be completely close to the bed symptoms. (2) Lumbar muscle strain: mostly related to long-term fatigue, lumbar muscle strain may cause lumbar muscles can not be completely relaxed, stimulating local edema and inflammation, muscle stiffness, pain, lying down the waist can not be completely against the bed and other symptoms. (3) Rheumatoid spondylitis: mostly induced by cold and fatigue, it can cause local small joint disorders of the spine, inflammation and stiffness of the joints of the lumbar region, which will further lead to the inability of the waist to lie down and stick to the bed completely. If the waist can not lie down completely close to the bed with pain, stiffness and other symptoms, it is recommended to consult a doctor in time to clarify the cause of the disease and then actively treat it, so as not to delay the condition.