Sudden pain in the posterior lumbar region can be caused by the following common reasons: 1. Acute trauma causing lumbar injury, including soft tissue contusion and bone injury, can produce sudden pain. 2. Visible in other systemic diseases, such as urinary stones, can lead to sudden pain in the posterior lumbar region. 3. Visible in tumors, including soft tissue tumors and bone tumors, and bone tumors are common in metastatic tumors, such as lung cancer Bone metastasis, which can also lead to local pathological fracture and sudden pain. So sudden pain in the posterior lumbar region, if there is no clear history of trauma, you must go to the hospital for detailed examination, which often leads to more serious diseases.