Rheumatoid arthritis is a chronic disease that can affect multiple joints throughout the body. The condition often starts in smaller joints, such as those found in the hand and wrist. It is symmetrical, meaning that it usually affects the same joint on both sides of the body.
Rheumatoid arthritis is an autoimmune disease. This means that the body’s immune system attacks its own tissues. In rheumatoid arthritis, the defenses that normally protect the body from infection instead damage normal tissue (such as cartilage and ligaments) and can soften bone.
Rheumatoid arthritis often affects the joint between the two bones of the forearm, the radius and ulna. The deformity in the ulna can cause wearing and possible rupture of the tendons that straighten your fingers. This can cause more deformity and loss of function in your hand.
The exact cause of rheumatoid arthritis is not known—there are no clear genetic or environmental factors. Although it is not an inherited disease, researchers believe that some people have genes that could make them more likely to have rheumatoid disease.
In this wrist with advanced rheumatoid arthritis, the alignment of the carpal bones has collapsed, leading to a loss of joint space between the bones.
Not all patients with arthritis will experience symptoms. When they do occur, the severity varies greatly from patient to patient. For some patients, the symptoms are not constant—but may come and go depending on their level of activity and other factors.
Symptoms of arthritis may include:
- Reduced range of motion or stiffness
- Weakness in the joint
Your doctor will talk with you about your overall health and medical history and ask you to describe your symptoms. He or she will perform a careful examination of your hand and wrist, looking for:
- Reduced range of motion
- Any areas of pain or tenderness
- Joint instability
- Swelling or other changes in appearance
During the examination, your doctor may also evaluate:
- Finger and thumb mobility—To determine how well your tendons and joints are functioning
- Nerve function—To determine if you have another condition that may be affecting your wrist, such as carpal tunnel syndrome (nerve compression)
X-rays. X-rays provide detailed images of dense structures, such as bone. X-rays of your wrist will help your doctor learn more about the exact location and severity of your arthritis. They can also help your doctor distinguish between various types of arthritis.
Blood tests. Your doctor may recommend blood tests to determine which type of arthritis you have. With rheumatoid and other types of inflammatory arthritis, blood tests are important for an accurate diagnosis. Osteoarthritis is not associated with blood abnormalities.