Bones, joints, and muscles

What is rheumatoid arthritis?

Rheumatoid arthritis is a chronic disease that causes pain, stiffness, and swelling in joints. Rheumatoid arthritis is often confused with osteoarthritis, a disease caused by wear and tear of joints over time. Rheumatoid arthritis, however, is not a condition of wear and tear, nor does it develop as a result of age or injury. Rather, it is an auto-immune disease. In rheumatoid arthritis, the body's own immune system does not function properly, and as a result, it mistakenly attacks healthy tissue in bones and joints, causing pain and swelling. Over time, those suffering from rheumatoid arthritis experience stiffness in their joints.¹ Affected joints may also lose their shape, resulting in a loss of movement; affected joints are no longer able to move within what is considered their normal range of motion. Movement causes undue pain and discomfort.²

What causes rheumatoid arthritis?

It's still unclear just what causes rheumatoid arthritis, but scientists and researchers believe it may be caused by a combination of genetic, environmental, or hormonal factors.

Genetic factors

Some researchers suggest that rheumatoid arthritis is genetic, occurring in families. The tendency to develop rheumatoid arthritis is related to specific genes. However, not all people who have these genes will develop rheumatoid arthritis. Similarly, people lacking these genes can still develop the disease. All of this suggests that other factors also play a role in the development of rheumatoid arthritis.³

Environmental factors

Some researchers believe there is a link between rheumatoid arthritis and exposure to bacteria or diet. In studies, scientists have found that patients with rheumatoid arthritis are more likely to have been exposed to a bacterium known as Proteus mirabilis than people without rheumatoid arthritis. Other bacterial or viral infections may also trigger the disease.⁴

Some types of auto-immune diseases are more common in certain parts of the world. Vitamin D is produced by the body when it has sufficient exposure to sunlight. This suggests that people who are unable to produce sufficient vitamin D—people living in Scandinavian countries, for example—are more likely to develop diabetes and arthritis.⁵

Hormonal factors

It's known that hormones such as estrogen and progesterone increase during pregnancy but decrease after birth. This may explain why rheumatoid arthritis often develops following childbirth. It may also explain why women suffering from rheumatoid arthritis may experience a significant improvement in their symptoms during pregnancy and why their RA flares up again after they've given birth.⁶

Who's at risk?

In general, it is often thought that arthritis affects only older adults. While it is true that rheumatoid arthritis generally affects people between the ages of 20 and 50, children can also develop a form of rheumatoid arthritis known as juvenile rheumatoid arthritis. Rheumatoid arthritis is two to three times more common in women than in men, supporting the belief that the disease may be caused—at least in part—by hormonal factors.⁷

Symptoms of rheumatoid arthritis

Typically, people with rheumatoid arthritis have tenderness, warmth and swelling around their joints. These symptoms commonly occur in a "symmetrical" pattern, meaning that if, for example, the left knee is affected, the right knee is also affected. While rheumatoid arthritis commonly affects the wrist and finger joints, it also occurs in the neck, shoulders, elbows, hips, knees, ankles, and feet. A common feature of rheumatoid arthritis is pain lasting longer than 30 minutes, particularly in the early morning or after periods of rest or inactivity. Other common symptoms include fatigue, an occasional fever, and a general sense of feeling rather unwell (malaise).⁸

Rheumatoid arthritis also carries other symptoms, including:⁹

• inflammation of the tear glands and salivary glands
• inflammation of the lining of the heart and lungs
• inflammation of the lungs themselves
• inflammation of the wrist and of the joints closest to the hand(s)
• symptoms persist for a long period of time
• symptoms may be present in other parts of the body, not just in the joints
• the appearance of small lumps of tissue (rheumatic nodules) under the skin of the hands, elbow or scalp, over the knee, or on the feet and heels

What happens in rheumatoid arthritis?

As we've already seen, rheumatoid arthritis is an autoimmune disease. Irritation and inflammation associated with rheumatoid arthritis occur when white blood cells, those cells responsible for fighting infection, accumulate in the synovial tissue. The synovial membrane is a fibrous sac containing the synovial fluid. The synovial fluid protects and lubricates the joint. More specifically, synovial fluid flows into and out of the cartilage in the joint, thereby providing nourishment and removing waste products.

White blood cells produce cytokines. The presence of cytokines can cause inflammation, resulting in pain and swelling. This is a normal process of the body when an infection exists, but it is inappropriate when infection is absent. The accumulation of cytokines in the synovial fluid attracts other immune cells to the affected area, causing the production of excess synovial fluid. In rheumatoid arthritis, several cytokines, including tumor necrosis factor-α, interleukin-1, and interleukin-8 appear to add to the ongoing destruction of cartilage, bone, and other joint tissues.⁹

Diagnosing rheumatoid arthritis

If you have any symptoms of arthritis and you suspect you may have the disease, consult your physician or other health care provider. Early diagnosis and treatment may mean less disability in the long run. Your doctor can diagnose arthritis through physical examination, x-rays, and bloodwork. Once a firm diagnosis of arthritis has been made, your doctor can then set up a treatment program to reduce the pain and disability associated with arthritis.

Treatment of rheumatoid arthritis

Many treatment programs are available, from medications such as aspirin, COX-2 specific inhibitors, analgesics, and nonsteroidal anti-inflammatory drugs to orthopedic surgery. Your doctor may also recommend physical or occupational therapy, rest, joint protection, and alternative therapies such as acupuncture.

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1. RA In-depth: An Up-To-Date Understanding of Rheumatoid Arthritis. Abbott Laboratories. (2004)
2. What is Rheumatoid Arthritis? About Arthritis. Arthritis.com (2003)
3. RA In-depth: An Up-To-Date Understanding of Rheumatoid Arthritis. Abbott Laboratories. (2004)
4. RA In-depth: An Up-To-Date Understanding of Rheumatoid Arthritis. Abbott Laboratories. (2004)
5. RA In-depth: An Up-To-Date Understanding of Rheumatoid Arthritis. Abbott Laboratories. (2004)
6. RA In-depth: An Up-To-Date Understanding of Rheumatoid Arthritis. Abbott Laboratories. (2004)
7. What is Rheumatoid Arthritis? About Arthritis. Arthritis.com (2003)
8. RA In-depth: An Up-To-Date Understanding of Rheumatoid Arthritis. Abbott Laboratories. (2004)
9. RA In-depth: An Up-To-Date Understanding of Rheumatoid Arthritis. Abbott Laboratories. (2004)