Lower back pain when lying on the bed may involve two factors, the first one is the existence of lumbar disorders, when lying on the bed there is irritating pain. The second is that the bed may be too soft or too hard, the lack of effective support for the lumbar spine, caused by chronic strain of the lumbar bones or muscles over time, resulting in irritating pain when lying down. If the lumbar spine exists disease, such as common lumbar muscle strain, lumbar spine degeneration and lumbar spine infection, etc., may be due to the disease stimulation of lumbar pressure increases when lying down, resulting in the emergence of pain. If the bed is too soft or too hard, lying on it when the lumbar lack of support, will lead to lumbar muscles or bones in a long-term state of tension or deformation of the state, over time is easy to cause strain and injury, resulting in pain when lying down.