Periosteum is a strong connective tissue envelope that covers the surface of the bone in addition to the joints. It is very densely attached to the bone at the bone ends and tendon attachment sites. At other sites, the periosteum is thick and easily peeled from the bone. The periosteum consists of two parts; the outer layer is made up of tightly bound collagen fibers, rich in blood vessels and nerves, and has a nutritional and sensory role. The inner layer, also called the formation layer, is thicker in collagen fibers and contains cells. The growing periosteum, with osteoblasts neatly arranged on its inner surface, has the function of osteoclasts and plays an important role in bone thickening and growth and fracture healing. The periosteum is rich in nerves and blood vessels. The causes of periostitis 1, the usual physical activity less: poor muscle coordination, suddenly increase the movement, sports technology is not good, etc., easy to make periosteal injury, periosteal vasodilatation congestion edema, or subperiosteal hemorrhage hematoma, mechanization, hyperplasia and inflammatory changes. 2, trauma or blood-borne infection periostitis: direct trauma to the periosteum, causing microbial infection can cause periostitis. Blood-borne microbial sources can also cause infected periostitis. Symptoms of periostitis 1, systemic symptoms Non-infectious periostitis systemic symptoms are mild. Only in acute hematogenous osteomyelitis, the systemic symptoms are severe. This patient often has anemia, dehydration and acidosis. 2, local symptoms osteomyelitis local pain, local congestion and edema, mobility disorders. In the early stages of hematogenous osteomyelitis, there is severe local pain and throbbing pain, protective muscle spasms, and limbs are afraid to move. Swelling and pressure pain in the affected area are obvious. If the lesion is close to the joint, the joint may also be swollen, but the pressure pain is not significant. When the abscess penetrates the bone and periosteum to the subcutaneous level, it fluctuates, and when it penetrates the skin, a sinus tract is formed, which does not heal over time. The treatment of osteochondritis requires attention to three aspects: timely diagnosis; timely and effective comprehensive treatment; timely functional exercise and good daily health care.