The causes of knee pain include osteoarthritis, gout, synovitis, joint injury, etc. For the causes, you can apply non-steroidal painkillers, uric acid-lowering medicines, and blood-activating painkillers. 1. Osteoarthritis: non-steroidal painkillers can be applied, such drugs are celecoxib capsules, aceclofenac delayed-release tablets, nimesulide dispersible tablets, ibuprofen delayed-release capsules. The pain relief effect is good, but there is a certain stimulation of the gastrointestinal tract. 2. Gout: apply uric acid-lowering drugs such as febuxostat tablets or allopurinol tablets, anti-inflammatory drugs such as colchicine tablets. 3. Synovitis: blood-activating and pain-relieving drugs such as synovitis granules or blood-activating and pain-relieving capsules can be applied. 4. Joint injury: including necessary meniscus injury, ligament injury and patellar chondromalacia, etc., need to be braked, hot compresses, local application of Yunnan Baiyao aerosol or orthopedic water. Knee pain should go to the hospital to identify the cause of further treatment.