Rheumatoid arthritis (RA) is an autoimmune disease caused by a problem with the immune system. In RA, the immune system attacks the healthy tissue of the joints and organs as though it is an outside invader, like a virus or bacteria.1
The exact cause of this immune system response is not fully understood. However, doctors have identified factors that may increase your risk of developing RA.1
Risk factors for RA
Smoking is known to increase your chance of developing RA. The increased risk is dependent on how long you have smoked and how heavily. Smoking may also make RA symptoms worse and cause treatment not to be as effective. If RA runs in your family, it may be a good idea to quit smoking to lower your risk.2
RA is also linked to hormones, but the exact relationship is not well understood. Women are 2 to 3 times more likely to develop RA than men. Studies show that certain hormonal factors women experience impact the chance of developing RA. For example, women who have never given birth may have a higher risk of developing RA. Additionally, RA may sometimes be triggered by events like menopause.2,3
Many factors have been studied for their relation to RA. So far, the research has not definitively proven a relationship between these factors and RA, but there may be a link. Some of these factors include:2
- Diet
- Weight
- Certain jobs or income
- Exposure to certain materials or chemicals, like silica dust
- Living with a smoker as a child
- Gum inflammation (gingivitis)
Genetics
While research suggests that RA is not directly inherited, genes may play a role in increasing a person’s chances of developing RA. Just as our DNA determines whether we have blue or brown eyes, our genes influence how our immune system works.1
Experts believe that people who develop RA inherit something in the genes involved in the formation and operation of our immune system that increases the chance it will attack healthy tissue. Though genetics could make someone more likely to have RA, other factors could impact whether they do develop it.1
Even though genetics may play a role in RA, it is not an inherited disease. If you have RA, you do not have to worry about passing it to your children or grandchildren. The risk to them is still low. If a parent has RA, the chances of their child also developing it are only around 1 to 3 percent.3
Triggers
One of the most poorly understood potential causes of RA are events that seem to bring it about. These are sometimes called triggers. Some people have found that their RA developed after giving birth or physical or mental trauma. Some research has backed up these claims, but it is still not clear why these events would trigger RA. More research is needed to understand this possible link.3
Because RA is an immune system response, there is some evidence that a virus could trigger it. Some people note their RA began around the same time as a viral-like illness. However, no infection has ever been identified as a cause for the RA immune system response.1
The exact causes of RA may never be understood. If you feel guilty that something you did caused your RA, you should not blame yourself. RA is very difficult to predict, and it is currently impossible to say if certain factors can cause or prevent it.