The swelling in knees is called knee effusion. This swelling could be because of an injury, overuse, or disease like rheumatoid arthritis. This can also be because of bursitis. This will cause pain and can restrict the movement. As there are a number of condition which may cause knee swelling and pain. So, its better to consult best orthopaedic surgeons and  get the necessary tests done for effective diagnosis and correct medical treatment. You may also contact best orthopaedic doctors at free doctor helpline and chat with doctors on line or talk to doctors over phone call and get health guidance.