Rheumatoid arthritis (RA) happens when your body's defenses – your immune system – targets your joint linings. RA affects joints on both sides of the body, such as both hands, both wrists, or both knees. This symmetry helps to set it apart from other types of arthritis. It can also affect the skin, eyes, lungs, heart, blood, or nerves.
Who’s Affected by Rheumatoid Arthritis?
About 1.5 million people in the United States have rheumatoid arthritis (RA). Nearly three times as many women have the disease as men. In women, RA most commonly begins between ages 30 and 60. In men, it often occurs later in life. Having a family member with RA increases the odds of having RA; however, the majority of people with RA have no family history of the disease.
Factors that may increase your risk of rheumatoid arthritis include:
- Your sex: Women are more likely than men to develop rheumatoid arthritis.
- Age: Rheumatoid arthritis can occur at any age, but it most commonly begins between the ages of 40 and 60.
- Family history: If a member of your family has rheumatoid arthritis, you may have an increased risk of the disease.
- Smoking: Cigarette smoking increases your risk of developing rheumatoid arthritis, particularly if you have a genetic predisposition for developing the disease. Smoking also appears to be associated with greater disease severity.
- Environmental exposures: Although uncertain and poorly understood, some exposures such as asbestos or silica may increase the risk for developing rheumatoid arthritis. Emergency workers exposed to dust from the collapse of the World Trade Center are at higher risk of autoimmune diseases such as rheumatoid arthritis.
- Obesity: People who are overweight or obese appear to be at somewhat higher risk of developing rheumatoid arthritis, especially in women diagnosed with the disease when they were 55 or younger.