Possible causes of pain on both sides of the knee include chronic injury, acute injury, metamorphosis, degenerative disease, etc. 1. Chronic injury: due to the excessive activities of the knee joint in daily life and work, resulting in cumulative damage to the articular cartilage, causing symptoms of pain on both sides of the knee. 2. Acute injury: If both sides of the knee are subjected to external force at the same time, causing local ligament injury, joint capsule injury, meniscus injury, dislocation and fracture, etc., which may lead to the symptoms. 3. Metabolic reaction: if the patient suffers from rheumatoid arthritis, gouty arthritis, ankylosing spondylitis, bacterial infection and other diseases, the symptoms may also appear. 4. Degenerative lesions: Pain on both sides of the knee may be caused by degenerative lesions such as osteoarthritis. With age and cumulative damage superimposed, the knee joint gradually degenerates, forming osteophytes and eventually osteoarthritis. Pain on both sides of the knee may also have other causes, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.