Difference Between Osteoarthritis and Rheumatoid arthritis

The reader should be aware of the differences between Osteoarthritis (OA) and Rheumatoid arthritis (RA) in order to understand both mainstream and alternative approaches to these disorders.

Osteoarthritis (OA) is the more common of the two in the general North American population, particularly among middle-aged and older adults. It is estimated to affect about 21 million adults in the United States, and to account for $86 billion in health care costs each year. It is also the single most common condition for which people seek help from complementary and alternative medical (CAM) treatments. The rate of OA increases in older age groups; about 70% of people over 70 are found to have some evidence of OA when they are X-rayed. Only half of these elderly adults, however, are affected severely enough to develop noticeable symptoms.

OA is not usually a disease that completely disables people; most patients can manage its symptoms by watching their weight, staying active, avoiding overuse of affected joints, and taking over-the-counter or prescription pain relievers. OA most commonly affects the weight-bearing joints in the hips, knees, and spine, although some people first notice its symptoms in their fingers or neck. It is often unilateral, which means that it affects the joints on only one side of the body.

The symptoms of OA vary considerably in severity from one patient to another; some people are only mildly affected by the disorder. OA results from progressive damage to the cartilage that cushions the joints of the long bones. As the cartilage deteriorates, fluid accumulates in the joints, bony overgrowths develop, and the muscles and tendons may weaken, leading to stiffness on arising, pain, swelling, and limitation of movement.

OA is gradual in onset, often taking years to develop before the person notices pain or a limited range of motion in the joint. OA is most likely to be diagnosed in people over 45 or 50, although younger adults are occasionally affected. OA affects more men than women under age 45 while more women than men are affected in the age group over 55. As of the early 2000s, OA is thought to result from a combination of factors, including heredity (possibly related to a mutation on chromosome 12); traumatic damage to joints from accidents, type of employment, or sports injuries; and obesity. It is not, however, caused by the aging process itself. Race does not appear to be a factor in OA, although some studies indicate that African American women have a higher risk of developing OA in the knee joints. Other risk factors for OA include osteoporosis and vitamin D deficiency.

RA, by contrast, is most likely to be diagnosed in adults between the ages of 30 and 50, two-thirds of whom are women. RA affects about 0.8% of adults worldwide, or 25 in every 100,000 men and 54 in every 100,000 women. Unlike OA, which is caused by degeneration of a body tissue, RA is an autoimmune disorder—one in which the body’s immune system attacks some of its own tissues. It is often sudden in onset and may affect other organ systems, not just the joints.

RA is a more serious disease than OA; 30% of patients with RA will become permanently disabled within two to three years of diagnosis if they are not treated. In addition, patients with RA have a higher risk of heart attacks and stroke. RA differs from OA, too, in the joints that it most commonly affects—often the fingers, wrists, knuckles, elbows, and shoulders. RA is typically a bilateral disorder, which means that both sides of the patient’s body are affected.

In addition, patients with RA often feel sick, feverish, or generally unwell, while patients with OA usually feel normal except for the stiffness or discomfort in the affected joints.