Arthritis in the hand occurs when joints are inflamed and may occur at the base of the thumb (the trapeziometacarpal joint), the middle joint of a finger, (the PIP joint) or in the metacarpophalangeal (MP) joint. The most common forms include osteoarthritis, post-traumatic arthritis and rheumatoid arthritis. Arthritis in the hand may be quite painful and greatly affect normal everyday activity. Symptoms of arthritis include stiffness, swelling and pain.