RA is an autoimmune disease. Your immune system is supposed to attack foreigners in your body, like bacteria and viruses, by creating inflammation. In an autoimmune disease, the immune system mistakenly sends inflammation to your own healthy tissue. The immune system creates a lot of inflammation that is sent to your joints causing joint pain and swelling. If the inflammation remains present for a long period of time, it can cause damage to the joint. This damage typically cannot be reversed once it occurs.
The exact cause of RA is not known. There is evidence that autoimmune conditions run in families. For instance, certain genes that you are born with may make you more likely to get RA. Smoking is also a known risk factor for causing RA.
- Age. The onset of RA is among adults in their 50s. Risk continues to increase with age for people assigned male at birth. RA often occurs in people assigned female at birth during their child-bearing years.
- Sex. People assigned female at birth are two to three times more likely to develop RA than people assigned male at birth.
- Genetics. People born with certain genes, called HLA class II genotypes, are more likely to develop RA. The risk of RA may be highest when people with these genes have obesity or are exposed to environmental factors like smoking.
- History of live births. People with ovaries who have may be at a greater risk of developing RA than those who have given birth.
- Early life exposure. According to the , children whose mothers smoked have double the risk of developing RA as adults.
- Smoking. Studies show that people who smoke cigarettes are at an increased risk of developing RA.
- Obesity. Having obesity can increase the risk of developing RA.
- Diet. High consumption of sodium, sugar (especially fructose), red meat, and iron is associated with an increased risk of developing RA.