Rheumatoid arthritis and osteoarthritis are the two most common types of arthritis, a condition that damages joints and affects their function.
The most common type of arthritis, osteoarthritis involves wear-and-tear damage to the cartilage that caps the bones in your joints. Rheumatoid arthritis occurs when your immune system mistakenly attacks the lining of your joints, causing a painful swelling that can eventually result in joint deformity.
While both rheumatoid arthritis and osteoarthritis can affect the small joints of the hand, there are differences. Rheumatoid arthritis tends to affect the middle joints of the fingers and the joints where the fingers attach to the hand. Osteoarthritis more commonly affects the joints at the ends of the fingers and at the base of the thumb.
In rheumatoid arthritis, the same joints usually are affected on both sides of the body. This symmetry doesn't typically occur in osteoarthritis, so it's common for only one hand or knee to be painful.
Joints damaged by osteoarthritis may be stiff in the morning, but they usually feel better in about 20 minutes. Joints affected by rheumatoid arthritis, on the other hand, often hurt for more than 45 minutes after you get out of bed.