The causes of knee pain in women in their twenties may be excessive exercise, osteoarthritis, rheumatoid arthritis, gout and so on. 1. Excessive exercise:Excessive exercise, commonly seen in people who love fitness and sports, can have a series of effects on the knee joint, such as increasing the joint load, wear and tear of articular cartilage, straining ligaments, which can cause anterior cruciate ligament injuries, medial collateral ligament injuries, meniscus injuries, etc., with symptoms such as knee joint pain, swelling and fluid accumulation. 2. Osteoarthritis: belongs to the knee joint aseptic inflammation, is a chronic joint disease, with osteophytes, joint cartilage degeneration, destruction as the main characteristics, clinical manifestations of joint deformity, activity limitation, joint swelling and pain. Advanced osteoarthritis is very harmful and can seriously affect the quality of life of patients. 3. Rheumatoid arthritis: it occurs in middle-aged and old women. Joint deformity, morning stiffness, joint pain and swelling are the main clinical manifestations. It may involve other organs, such as lungs and blood vessels, thus causing corresponding symptoms. 4. Gout: localized precipitation of urate crystals in the knee joint, causing knee pain. Usually should establish a good diet, it is recommended to drink more water, low purine diet, is conducive to the discharge of uric acid, relieve symptoms. Women alone can not accurately determine the cause of knee pain symptoms, but also need to be combined with the characteristics of the medical history, other test results in order to make an accurate judgment, it is recommended that the cause of the disease under the guidance of a doctor.