Arthritis literally means inflammation in the joint. It can cause pain, swelling, and limitation in range of motion of a joint. When I talk about different types of arthritis, some of my patients are surprised- “What, you mean there is more than one kind of arthritis?”
The answer is yes. In fact, there are more than 100! The most common type of arthritis is osteoarthritis, affecting 3 out of 5 of us by the time we are 65. Most people have also heard of rheumatoid arthritis, which is an autoimmune disease, and gout, which is caused by deposits of uric acid crystals in a joint. There is also arthritis caused by infection, deposition of other crystals, and many connective tissue diseases such as lupus or scleroderma.
So how do we differentiate between the different types of arthritis? I usually like to divide them into two categories:
1) Mechanical arthritis
2) Inflammatory arthritis
Mechanical arthritis would include osteoarthritis which is caused by wear and tear of a joint. Also in this category would be joint pain caused by trauma, tendonitis or tendon rupture. Even though there may be a lot of fluid in the joint, there are usually not too many white blood cells in the fluid- ie the fluid is not inflammatory.
I include just about everything else under “Inflammatory arthritis”. The immune system is usually involved in these forms of arthritis, causing there to be a lot of white blood cells in the joint fluid. Examples are rheumatoid arthritis, gout, psoriatic arthritis, and others.
Why is this important? Because different types of arthritis are treated very differently. Glucosamine, which may be helpful in osteoarthritis, will not help gout. Miracle drugs for rheumatoid arthritis, like Enbrel and Humira, are actually dangerous if the arthritis is caused by an infection.
So I would say that if you are experiencing joint pain, the most important first step is to find out what type of arthritis you actually have. You can then work with your rheumatologist to come up with the best treatment option for you.