Young women with knee pain, generally caused by the following causes: 1, patellofemoral arthritis, Bin femoral arthritis is common in patients with long-term knee sports, long-term walking with the knee chronic strain, which can lead to chronic inflammation of the patellofemoral joint of the knee, which has cartilage damage, resulting in joint pain, especially in up and down stairs, hiking knee pain is more obvious. Early examination of knee x-ray and MRI is required for diagnosis; 2. Patellar tendonitis or quadriceps tendonitis, both of which can also cause pain above and below the patella, with limited knee movement. This is diagnosed by early physical examination and early MRI of the knee joint; 3. Synovitis, which can also have pain and swelling of the knee joint and joint effusion. This is diagnosed by early examination of the body, ultrasound and MRI; 4. Tumors, when there are tumors in the soft tissues and bones of the knee joint, there can be knee pain, which is diagnosed by early examination of MRI of the knee joint.