Both modifiable and non-modifiable risk factors are responsible for causing rheumatoid arthritis. Gender, genetics, and age are among non-modifiable risk factors whereas environmental factors and body weight are among modifiable risk factors. The major risk factors for the rheumatoid arthritis are:

  • Gender: Rheumatoid arthritis can develop in any age, gender, and ethnic group, but women are more susceptible to develop it. Women are generally diagnosed with this condition between the ages of 30 and 60 years. However, men are generally diagnosed with it later because the risk increases with age.
  • Environmental risk factors: Environmental risk factors can also raise the risk of developing rheumatoid arthritis. Some environmental risk factors that increase the risk of rheumatoid arthritis are as follows:
  • Smoking: Smoking is one of the major environmental risk factors for the development of rheumatoid arthritis. Prolonged smoking can cause the increase in the concentration of a substance called rheumatoid factor. The presence of rheumatoid factor in the blood indicates the malfunctioning of the immune
  • Silica dust exposure: Another environmental risk factor for rheumatoid arthritis is silica dust which mainly affects the people who are working in the mining industry. This factor mainly affects the people those have ACPA-positive rheumatoid arthritis.
  • Mineral oils: Mineral oils have the ability to activate the immune system. Studies show that the high levels of occupational exposure to hydraulic oil are linked with increased risk of developing rheumatoid arthritis.
  • Infections: Some sort of infection may play a role in stimulating rheumatoid Micro-organisms linked with risk for rheumatoid arthritis include parvovirus B19, Proteus and Chlamydia.
  • Age: Rheumatoid arthritis can develop at any age, but the susceptibility increases with age. The risk of onset of rheumatoid arthritis is higher for adults in their sixties.
  • Obesity: Obese people have more risk of rheumatoid arthritis.

Association Between the Development of Rheumatoid Arthritis and Inheritance

In the case of rheumatoid arthritis there are some genes that increase its risk. HLA-DR4 is the gene associated with the development of rheumatoid arthritis. 60-70% of the patients of rheumatoid arthritis of European ancestry carry the HLA-DR4 gene as compared to the 30% of the general population. This happens because the proteins generated from HLA genes assist the immune system to differentiate the proteins of their own body from proteins produced by foreign invaders. There are some other genes also that increase the risk of rheumatoid arthritis as they control the immune responses. But it is not that everyone who carries these genes will develop rheumatoid arthritis.

Some of the other genes that increase the risk of rheumatoid arthritis are:

  • STAT4: This gene has a role in activating and regulating the immune system.
  • TRAF1 and C5: This gene has a role in causing chronic inflammation.
  • PTPN22: This gene is linked with the onset of rheumatoid arthritis and with the progression of the disease.

Some of the genes which are thought to be responsible for rheumatoid arthritis are also linked with other autoimmune diseases as multiple sclerosis and type 1 diabetes.