Back leg pain has several factors as follows: First, the most common factor is orthopedic surgical factors, such as lumbar disc herniation, lumbar disc bulge, sciatica, sacroiliac arthritis when the compression of the lumbar nerve root, resulting in pain in the lumbar area that innervates the nerve root of the lower leg. Second, the back leg pain and rheumatic diseases, rheumatoid diseases, such as rheumatoid arthritis, rheumatoid arthritis, there will be redness, swelling, pain and other joint dysfunction of the back leg. Third, the pain in the hind legs is also related to infectious factors, such as the legs are susceptible to bacterial, viral, fungal and other pathogenic microbial infections, at this time, if there is a double lower extremity soft tissue swelling, cellulitis or dengue will lead to pain, accompanied by the skin temperature of the hind legs increase in the situation. Fourth, peripheral neuritis patients will also appear in the hind legs of the pain, such as diabetes combined with peripheral radiculitis, will lead to the symptoms of pain in the hind legs.