Causes and Risk Factors
Actual Cause Is Unknown
Scientists believe that rheumatoid arthritis may result from the interaction of many factors such as genetics, hormones, and the environment. Although rheumatoid arthritis sometimes runs in families, the actual cause of rheumatoid arthritis is still unknown.
Research suggests that a person's genetic makeup is an important part of the picture, but not the whole story. Some evidence shows that infectious agents, such as viruses and bacteria, may trigger rheumatoid arthritis in people with an inherited tendency to develop the disease. However, a specific agent or agents are not yet known.
It is important to note that rheumatoid arthritis is not contagious. A person cannot catch it from someone else.