In the UK, rheumatoid arthritis affects more than 400,000 people.
It often starts when a person is between 40 and 50 years old. Women are 3 times more likely to be affected than men.
In rheumatoid arthritis, the body’s immune system targets affected joints, which leads to pain and swelling.
The outer covering (synovium) of the joint is the first place affected.
This can then spread across the joint, leading to further swelling and a change in the joint’s shape. This may cause the bone and cartilage to break down.
People with rheumatoid arthritis can also develop problems with other tissues and organs in their body.
