What happens to my joints?
RA varies a lot from person to person. Although it can affect almost any joint, the small joints of the fingers, thumbs, wrists, feet and ankles are most commonly affected. Knees and shoulders can also be affected and, less commonly, elbows, hips, neck and other joints. Most people are affected in more than one joint. RA usually affects both sides of the body – not always at once, but usually within a very short space of time.
What actually happens to my joints?
To explain what happens in RA, it helps to understand how a normal joint works.
Joints are like hinges between bones. These hinges are made up of ligaments, muscles and tendons which all work together to let the joint move. Little sacs – or pouches – called ‘bursae’ hold fluid which coats the joint to help it move easily. The bones themselves have a coating of slippery cartilage which makes movement smoother.
For further protection, the joint is lined on the inside by a thin layer of tissue called the ‘synovial’ membrane. This membrane produces a thick lubricant called synovial fluid, which provides nutrients to the joint to keep it healthy.
In RA, your immune system aggressively targets your joints and they become inflamed. The inflammation particularly affects:
- the synovial membrane
- the tendon sheaths (tubes in which the tendons move)
- the bursae
The joint swells and the inflamed tissues in the joint become stiff, painful and swollen. If the inflammation isn’t tackled, it can damage the joints.
We now know that much of this damage can happen in the first months and years of RA. This is why it is vital to get an early diagnosis so that you can get treatment before lasting damage is done.