The cause of rheumatoid arthritis (RA) is unknown. However, RA involves an attack on the body by its own immune cells (auto-immune disease). Different cases may have different causes. Infectious, genetic, and hormonal factors may play a role.
The disease can occur at any age, but it begins most often between the ages of 25 and 55. The disease is more common in older people. Women are affected 2.5 times more often than men. Approximately 1-2% of the total population is affected. The course and the severity of the illness can vary considerably.
The onset of the disease is usually gradual, with fatigue, morning stiffness (lasting more than one hour), diffuse muscular aches, loss of appetite, and weakness. Eventually, joint pain appears, with warmth, swelling, tenderness, and stiffness of the joint after inactivity.
Joint involvement in RA usually affects both sides of the body equally -- the arthritis is therefore referred to as symmetrical. Wrists, fingers, knees, feet, and ankles are the most commonly affected joints. Severe disease is associated with larger joints that contain more synovium (joint lining).
When the synovium becomes inflamed, it secretes more fluid and the joint becomes swollen. Later, the cartilage becomes rough and pitted. The underlying bone eventually becomes affected. Joint destruction begins 1-2 years after the appearance of the disease.
Characteristic deformities result from cartilage destruction, bone erosions, and tendon inflammation and rupture. A life-threatening joint complication can occur when the cervical spine becomes unstable as a result of RA.
Other features of the disease that do not involve the joints may occur. Rheumatoid nodules are painless, hard, round or oval masses that appear under the skin, usually on pressure points, such as the elbow or Achilles tendon. These are present in about 20% of cases and tend to reflect more severe disease.
On occasion, they appear in the eye where they sometimes cause inflammation. If they occur in the lungs, inflammation of the lining of the lung (pleurisy) may occur, causing shortness of breath.
Anemia may occur due to failure of the bone marrow to produce enough new red cells to make up for the lost ones. Iron supplements will not usually help this condition because iron utilization in the body becomes impaired. Other blood abnormalities can also be found, for example, platelet counts that are either too high or too low.
Rheumatoid vasculitis (inflammation of the blood vessels) is a serious complication of RA and can be life-threatening. It can lead to skin ulcerations (and subsequent infections), bleeding stomach ulcers (which can lead to massive hemorrhage), and neuropathies (nerve problems causing pain, numbness or tingling).
Vasculitis may also affect the brain, nerves, and heart causing strokes, sensory neuropathies (numbness and tingling), heart attacks, or heart failure.
Heart complications of RA commonly affect the outer lining of the heart. When inflamed, the condition is referred to as pericarditis. Inflammation of heart muscle, called myocarditis, can also develop. Both of these conditions can lead to congestive heart failure characterized by shortness of breath and fluid accumulation in the lung.
Lung involvement is frequent in RA. Fibrosis of the lung tissue leads to shortness of breath and has been reported to occur in 20% of patients with RA. Inflammation of the lining of the lung, called pleuritis, can also lead to fluid accumulation. Pulmonary nodules, similar to rheumatoid nodules, can also develop.
Eye complications include inflammation of various parts of the eye. These must be screened for in RA patients.
