Knee pain and swelling can be caused by a variety of reasons: 1. Local osteophytes or knee degeneration may cause pain and swelling in the knee joint. 2. Having knee synovitis can also cause local pain and swelling. 3. Specific diseases of the knee joint, such as gouty arthritis or systemic reactive arthritis, can also cause pain and swelling in the knee joint. 4. Rheumatoid arthritis can also Knee pain and swelling can occur. If you have pain and swelling in the knee joint, you should go to the hospital. After a medical examination by a professional doctor, appropriate tests should be prescribed to rule out special types of arthritis such as gouty arthritis and rheumatoid arthritis.