Rheumatoid arthritis is an autoimmune condition, which means it's caused by the immune system attacking healthy body tissue. However, it's not yet known what triggers this.
Your immune system normally makes antibodies that attack bacteria and viruses, helping to fight infection.
If you have rheumatoid arthritis, your immune system mistakenly sends antibodies to the lining of your joints, where they attack the tissue surrounding the joint.
This causes the thin layer of cells (synovium) covering your joints to become sore and inflamed,releasing chemicals that damage nearby:
If the condition isn't treated, these chemicals gradually cause the joint to lose its shape and alignment.Eventually, it can destroy the joint completely.
Various theories of why the immune system starts to attack the joints have been suggested, such as an infection orvirus being a trigger, but none of these theories has been proven.
There are a number of things that may increase your risk of developing rheumatoid arthritis, including:
Read about rheumatoid arthritis, a long-term condition that causes pain, swelling and stiffness in the joints.
Rheumatoid arthritis mainly affects the joints, although it can cause problems in other parts of the body too.
Read about the causes of rheumatoid arthritis. Rheumatoid arthritis is an autoimmune condition, which means it's caused by the bodys immune system attacking itself
Read about diagnosing rheumatoid arthritis. It can be difficult to diagnose because many conditions cause joint stiffness and inflammation
Read about treating rheumatoid arthritis. Treatment can help reduce inflammation in the joints, relieve pain and prevent or slow joint damage.
Read about living with rheumatoid arthritis. It can be life-changing and you may need long-term treatment to control your symptoms and reduce joint damage.
Read about complications of rheumatoid arthritis. Having rheumatoid arthritis can put you at a higher risk of developing other conditions
Paul Casimir has been living with arthritis for half his life, but he doesnt let it stop him doing the things he enjoys.
Jonathan Gledhill was diagnosed with rheumatoid arthritis when he was 27. He explains how arthritis affects his life.