There are many reasons for lumbar pain with leg pain, such as lumbar vertebral osteophytes, lumbar intervertebral disc herniation, lumbar dorsal fasciitis, autoimmune diseases and osteoporosis. 1. Lumbar vertebral osteophytes: lumbar vertebral osteophytes occur in the lumbar 3, lumbar 4 vertebrae, clinically, there can be lumbar soft tissue pain, lumbar spine pain, distension, and even cause bending limitations. If osteophytes compress the sciatic nerve, they can radiate to the lower limbs, causing lumbar pain along with leg pain. 2. Herniated lumbar intervertebral disc: lumbar intervertebral disc due to localized compression, irritation and compression to the sciatic nerve, so there will be leg pain, leg numbness, lumbar pain and other phenomena, and thus lumbar pain with leg pain. 3. Lumbar dorsal fasciitis: Lumbar dorsal fasciitis will not only cause lumbar pain, but the pain can also radiate to the thigh or calf, thus causing lumbar pain with leg pain. 4. Autoimmune diseases: rheumatoid arthritis, rheumatoid arthritis, ankylosing spondylitis and other diseases can also lead to back pain with leg pain. 5. Osteoporosis: when osteoporosis occurs, it can cause pain in all parts of the body and joints, so the clinical symptoms of back pain with leg pain can appear. There are many causes of back pain with leg pain, such as high fever can also appear back pain with leg pain, after the emergence of symptoms, it is recommended that patients go to the hospital in a timely manner to improve the examination to identify the cause of the disease, and then actively cooperate with the doctor to carry out standardized treatment.