The most common cause is muscle strain and inflammation of the lumbar back, mainly due to prolonged sitting, or bending heavy physical labor, and muscle strain and inflammation of the lumbar back, resulting in soreness, swelling and pain, and night rest pain, that is, sleeping until the second half of the night, suddenly feel pain in the lumbar back, and even wake up in pain, how to change position pain can not be reduced. 2.Lower back pain caused by nerve compression due to lumbar disc herniation, if the degree of disc herniation is heavy, the nerve compression is more obvious, then there will be continuous lower back pain, and sometimes even combined with radioactive pain to the lower extremities. 3.Rarely, is the tumor or bone destruction of the vertebrae in the lower back, such as infection, tuberculosis lesions, such pain usually appears at night This pain is also called nocturnal resting pain, which is more intense and cannot be relieved by changing the position, and often requires medication.