What Causes Swelling and Pain in the Right Leg?

Some causes of swelling and pain in a leg can include deep vein thrombosis, gout and knee bursitis. Many conditions can cause these symptoms in different parts of the legs, such as different types of arthritis, sprains or an infection. In particular, rheumatoid arthritis is an autoimmune inflammatory condition in which there is swelling in the affected leg joints and pain may be present, as noted by Mayo Clinic.