The exact cause of rheumatoid arthritis is not known. It is thought to be an interaction between genetic, environmental and hormonal factors leading to an autoimmune reaction (i.e. body’s immune system fails to recognise tissues as its own, considering them as foreign and therefore attacks them) causing inflammation and eventually destruction and deformity of the joints.

Genetic factors increase susceptibility to the disease. Rheumatoid arthritis tends to run in families.

Environmental factors can trigger the onset of the disease in susceptible persons. A number of infectious agents have been identified (viruses such as Epstein -Barr virus, parvo virus and certain bacteria such as staphylococcus, streptococcus).

Hormonal factors are believed to accelerate or retard the disease progress. Incidence of rheumatoid arthritis is higher around menopause (perimenopausal age) in females. Oral contraceptives with progesterone (a female hormone) have a protective effect.


Age: Even though the disease may occur at any age, the incidence is higher around 20-40 years of age.

Sex Women, especially around menopause are affected three times more than men.