There are many causes of knee pain, and treatment varies from disease to disease and condition to condition; there is no one treatment for all diseases. Common diseases of knee pain include trauma, osteoarthritis, septic infection of the knee joint, etc. Treatment includes conservative treatment, anti-infection treatment, joint puncture treatment, surgery, etc. 1. Trauma: Knee trauma can cause edema, bruising of the muscles around the joint, intra-articular fracture and so on. For patients without fracture or serious structural damage can take the treatment measures of braking and resting. If there is a lot of fluid or blood in the joint, arthrocentesis can be chosen to extract the fluid. Intra-articular fracture of the knee joint mostly involves the joint surface, so in order to minimize the after-effects, surgical treatment is often chosen. 2. Osteoarthritis: Osteoarthritis can be treated conservatively in the early stage, including rest, reducing weight bearing, physical therapy, acupuncture and so on. When the pain is severe, oral painkillers such as celecoxib can be taken. If conservative treatment is ineffective, pain worsens progressively, or severe deformity occurs, surgery can be considered, including arthroscopic or open surgery. 3. Knee septic infection: Knee septic infection requires systemic anti-infective treatment, commonly used antibiotics include ceftriaxone, amoxicillin, levofloxacin and so on. Antibiotics can also be injected into the joint cavity after puncture and fluid extraction. For the antibiotic treatment is not effective patients need to take arthroscopic surgery or continuous joint cavity irrigation. Patients with knee pain are advised to go to the hospital as soon as possible for prompt identification of the cause of the problem and appropriate treatment. Drug treatment should be under the guidance of a doctor, avoid self-medication.