A herniated lumbar disc will cause lumbar pain in most cases for the following reasons: 1. The nucleus pulposus protrudes from the ruptured annulus fibrosus, and because there is rich innervation in the annulus fibrosus, the rupture of the annulus fibrosus and the protrusion of the nucleus pulposus to stimulate the nerves in the annulus fibrosus will cause local neuroinflammation and local pain, and the pain will be mainly in the lumbar area. When the herniated nucleus pulposus breaks through the fibrous ring to the spinal canal, the compression of the spinal nerve root will cause neuralgia, and the pain will mainly radiate to the feet, including unilateral or bilateral lower limb pain, sometimes accompanied by numbness. 2. Patients with lumbar disc herniation are often accompanied by chronic lumbar muscle strain, which can also cause lumbar pain due to being in a state of muscle spasm.