Rheumatoid arthritis is actually one of a number of related diseases that affect the connective tissues of the body. RA generally refers to the joints of the body, but systemic symptoms such as weakness, tiring easily and involvement of the tissues in the lung can also be present. Common symptoms of joint involvement include pain, swelling, redness, feeling warm to the touch and limited mobility or range of motion in the affected joint.
Rheumatoid arthritis is a chronic disease that varies from manifesting mild and occasional pain to a severe form that produces joint deformity. Individuals with the more severe form of arthritis may have limited physical abilities and difficulty managing equipment. In addition, individuals with pulmonary complications of rheumatoid arthritis would be at risk for arterial gas embolism for any depth of diving. The disease varies from individual to individual, but it usually produces pain.
Theoretically, because of altered blood flow distribution and other factors, an affected joint might make the diver more susceptible to decompression illness (DCI). Also, it may be difficult to distinguish the pain due to rheumatoid arthritis from that due to DCI. Divers who are having "flare-ups" should therefore probably wait until their symptoms have resolved before scuba diving. In an active, healthy and otherwise physically fit individual, there should be no reason for a person with rheumatoid arthritis to avoid scuba diving if cleared by a physician.