Rheumatoid arthritis (RA) is a long-term disease that causes inflammation of the joints and surrounding tissues. It can also affect other organs.

The cause of RA is unknown. It is considered autoimmune disease. The body's immune system normally fights off foreign substances, like viruses. But in an autoimmune disease, the immune system confuses healthy tissue for foreign substances. As a result, the body attacks itself.

RA can occur at any age. Women are affected more often than men.

RA usually affects joints on both sides of the body equally. Wrists, fingers, knees, feet, and ankles are the most commonly affected. The course and the severity of the illness can vary considerably. Infection, genes, and hormones may contribute to the disease.

The disease usually begins gradually with:

• Fatigue
• Morning stiffness (lasting more than 1 hour)
• Widespread muscle aches
• Loss of appetite
• Weakness

Eventually, joint pain appears. When the joint is not used for a while, it can become warm, tender, and stiff. When the lining of the joint becomes inflamed, it gives off more fluid and the joint becomes swollen. Joint pain is often felt on both sides of the body, and may effect the wrist, knees, elbows, fingers, toes, ankle or neck.

Additional symptoms include:

• Anemia due to failure of the bone marrow to produce enough new red cells
• Eye burning, itching, and discharge
• Hand and feet deformities
• Limited range of motion
• Low-grade fever
• Lung inflammation (pleurisy)
• Numbness or tingling
• Paleness
• Round, painless nodules under the skin (usually a sign of more severe disease)
• Skin redness or inflammation
• Swollen glands

Joint destruction may occur within 1-2 years after the appearance of the disease.

A specific blood test is available for diagnosing RA and distinguishing it from other types of arthritis. It is called the anti-CCP antibody test. Other tests that may be done include:

• Complete blood count
• C-reactive protein
• Erythrocyte sedimentation rate
• Joint x-rays
• Rheumatoid factor test (positive in about 75% of people with symptoms)
• Synovial fluid analysis