Rheumatoid arthritis (roo-ma-toy-d arth-ri-tus) is a condition that can cause pain, swelling and stiffness in joints.
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It is known as an autoimmune condition. This means that the immune system, which is the body’s natural self-defence system, gets confused and starts to attack your body’s healthy tissues.
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In rheumatoid arthritis, the main way it does this is with inflammation (in-fla-may-shun) in your joints.
Rheumatoid arthritis affects around 400,000 adults aged 16 and over in the UK. It can affect anyone of any age. It can get worse quickly, so early diagnosis and intensive treatment are important.
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The sooner you start treatment, the more effective it’s likely to be. To understand how rheumatoid arthritis develops, it helps to know how a normal joint works.