The common causes of knee and ankle pain are chronic strain, osteoarthritis, rheumatoid arthritis, gouty arthritis and so on. 1. Chronic strain: if you run, jump and other sports for a long time, it is easy to cause knee and ankle joint strain, when stimulated by external cold, it can cause knee and ankle pain. 2. Osteoarthritis: due to various factors causing damage to the cartilage cells, and then secondary osteophytes, causing joint pain in the body, which is common in traumatized or middle-aged and elderly people, and can show pain in the knee and ankle joints, and in severe cases, stiffness of the joints may also occur. 3. Rheumatoid arthritis: This is an autoimmune disease. When rheumatoid arthritis attacks acutely, it can involve many joints of the whole body, with redness, swelling and pain, including the knee and ankle joints. 4. Gouty arthritis: If the uric acid level in patients with gout is not well controlled for a long time, it is easy to form gout stones in the knee and ankle joints, and when the uric acid level in patients’ bodies exceeds the standard, it will induce joint pain in patients. Causes of knee and ankle pain are more reasons, if the symptoms do not get better after resting, it is recommended to go to the hospital in time to identify the cause of the disease, targeted treatment.