Rheumatoid Arthritis: Causes and Risk Factors
Rheumatoid arthritis (RA) develops when part of the immune system, which is supposed to protect you from outside invaders, instead attacks your joints. It's not fully understood what causes the immune system to malfunction in this way, but RA is believed to be influenced by a combination of genetic susceptibility and environmental factors.
Rheumatoid Arthritis Risk Factors
Your genes: People with a family history of rheumatoid arthritis are more likely to develop it themselves, and susceptibility to this disease has been traced to specific genes. But not everyone with a genetic predisposition gets RA, which suggests there may be other causes of rheumatoid arthritis.
Your environment: Environmental triggers may help set off rheumatoid arthritis in people who already have a genetic susceptibility. Research suggests a viral or bacterial infection is the most likely trigger, but other environmental factors that may play a part include prolonged exposure to cigarette smoke and/or silica dust.
Gender: Although being a woman doesn’t cause rheumatoid arthritis, your gender can be a significant risk factor. Women are two to three times more likely than men to develop rheumatoid arthritis. The reason for this is unclear, although there's some evidence that hormones -- particularly estrogens -- may play a role in RA.
Age: Rheumatoid arthritis usually begins between the ages of 30 and 60, but it can develop at any time.
Smoking: Smoking -- and exposure to secondhand smoke – is among the top rheumatoid arthritis risk factors. It may also increase the severity of the disease.
Ethnicity: Rheumatoid arthritis occurs in people of all ethnicities, but some American Indian and Alaskan Native populations have a significantly higher incidence of RA than other ethnic groups.
