Rheumatoid arthritis or RA is an inflammatory disorder. It can affect every system in a person’s body, but primarily affects the joints, especially the hands, feet, wrists, knees and ankles. The joints become stiff, painful, swollen and warm to the touch. The skin over the joint has a purplish color and as time goes on the joints of the hands and feet deform.
Rheumatoid arthritis is not the same condition as osteoarthritis, which occurs when the cushioning cartilage between joints begins to deteriorate from the wear and tear of living. Doctors do not really know what triggers the onset of rheumatoid arthritis, though some believe a bacteria or virus stimulates the patient’s immune system in an abnormal way. Here are five facts about the condition:
1. It Mostly Affects Women
According to Texas Orthopedics, Sport & Rehabilitation Associates, rheumatoid arthritis affects women three times as often as it does men, but men’s symptoms tend to be more severe. The disease can strike at any age, but it usually happens when the patient is in their 60s.
2. It is probably an Autoimmune Disease
Doctors also suspect that RA is an autoimmune disease. This means that the patient’s own immune system, which is meant to fight foreign invaders and pathogens, is attacking their body. In this case, the body is attacking its own joints, though it can attack other organs. The white blood cells of the immune system travel to the joints and cause inflammation in the tissue that lines the joints, or the synovium. This destroys the cartilage and causes swelling that ultimately damages the bone. Unlike osteoarthritis, when one joint of the body is attacked by rheumatoid arthritis, the opposite joint is also affected.
3. About One to Three Percent of the Population Has Rheumatoid Arthritis
In 2005, 1.5 million people 18 years of age or older had rheumatoid arthritis, according to the Centers for Disease Control and Prevention. About 41 per 100,000 people will contract RA. There are indications that as of 2016 the disease is increasing among women and may be increasing among men.
4. Rheumatoid Arthritis is Difficult to Diagnose
The condition is especially difficult to diagnose in its early stages, though it is recognizable when it is quite advanced. Tests used to detect rheumatoid arthritis include the rheumatoid factor antibody test. People with RA test positively with this test, though people who don’t have the disease can also test positively. Doctors need to evaluate the patient’s other symptoms, especially their joint problems, to make a confident diagnosis.
Another test is used to find anti-cyclic citrulline peptide antibodies in the patient’s body. If these antibodies are present, the patient may have an aggressive type of rheumatoid arthritis. Other tests detect elevated C-reactive protein levels or a high erythrocyte sedimentation rate (ERS). These indicate inflammation. A positive antibody test (ANA) means the patient has an unspecified autoimmune condition.
Mostly, doctors rely on their patients’ descriptions of their symptoms. Imaging tests also help doctor and patient monitor the disease’s progression.
5. Rheumatoid Arthritis Probably Has a Genetic Component
Researchers found that many RA patients share genetic markers, including the HLA-DRw4, DRBI and PTPN22 molecules. The last is the strongest indicator that a person will develop rheumatoid arthritis, for PTPN22 is implicated in other autoimmune diseases. But even the presence of these markers does not guarantee that a person will go on to develop RA. Researchers are certain there must be environmental factors involved in developing RA. For example, it is very unusual for both identical twins to develop rheumatoid arthritis.
Environmental and hormonal factors do seem to affect the risk of getting rheumatoid arthritis. People who smoke or whose mothers smoked while they were in the womb seem to have a higher risk for RA, as do women who have never given birth, who had an early menopause and who had or have polycystic ovarian syndrome. Women who used birth control pills and who breastfed had a smaller risk.