When rheumatoid arthritis flares up, it makes joints feel stiff and achy. That discomfort may go away at times, but there may still be permanent damage. Eventually rheumatoid arthritis can harm joints so they don't work as well even when the disease itself is not active. How does joint damage occur, and how can it be prevented?
Doctors call the active periods of rheumatoid arthritis disease activity. During disease activity, infection-fighting cells (white blood cells) are mistakenly allowed into the joint. No one understands why this happens, but it's clear the white blood cells don't belong there.
Inside the joint, these white blood cells produce chemicals that they usually use to kill invading microorganisms -- only no microorganisms are there. Instead, the chemicals damage the healthy joint tissue. During high levels of disease activity, you experience a flare -- joints become swollen, stiff, and painful. You can also have low levels of disease activity that come and go without your feeling any symptoms.
There are two main ways this process can cause joint damage:
The infection-fighting chemicals cause cartilage to slowly degrade. Cartilage is the cushion between bones in a joint. Over time, putting stress on the joint or bearing weight on it can wear down the weak cartilage more. This is called degenerative disease, and it is similar to what happens in "regular" or "wear and tear" arthritis (osteoarthritis) -- only it happens faster in people with rheumatoid arthritis.
The inflammation inside the joint stimulates the joint lining (synovium) to grow and spread where it doesn't belong. If it continues long enough, it can harm healthy cartilage or bone.
The simple rule of thumb is, the "longer" and "stronger" the disease activity, the more joint damage is probably occurring.
A person with joint swelling and stiffness every day is more likely to have joint damage than a person with these symptoms once a month. (Longer disease activity)
Someone with a lot of joint swelling is more likely to have damage than a person with just a little bit. (Stronger disease activity)
How can you tell if you are having disease activity? It can sometimes be difficult.
You can be feeling a lot of pain, yet suffer no damage to your joints.
Joint damage can also occur without causing any pain.
Joint swelling is a reliable sign, though. For the most part, having joint swelling is proof of having ongoing disease activity.
The length of morning stiffness each day is also useful. Ask yourself, after getting up, "How long does it take until I'm feeling as loose as I'll feel for the day?" The longer you feel stiff, the more likely it is that your rheumatoid arthritis is active.
Another sign you can look for is a "boggy" joint. When the joint lining begins to grow abnormally, it may give a joint a mushy texture. This boggy texture may remain even when you are not having a flare. If you notice this happening, you should see your rheumatologist.