As mysterious as the causes of rheumatoid arthritis (RA) are, there are a number of clear risk factors that increase a person's chance of developing RA.

Gender

Women account for roughly 70 percent of all RA sufferers, making them far more likely than men to be diagnosed with the disease.

Age

The majority of all RA diagnoses happen between ages 40 and 60. Some people do develop RA as children or as younger adults, but this is comparatively rare.

Family History

If a member of your family has RA, you are more likely to be diagnosed as well. Rheumatoid arthritis is not an inherited condition like some other genetic diseases, but it is thought that genetics affect a person's susceptibility to RA.

Smoking

Cigarette smokers are more likely than nonsmokers to develop RA. Smokers who are diagnosed also tend to have more severe symptoms and are more difficult to treat effectively. However, quitting smoking reduces these risks.