Pain and tenderness on the thumb side of your wrist may be due to de Quervain’s tenosynovitis.  Tendons connect muscles to bone. Two of the tendons that move your thumb run along the thumb side of your wrist. As with all tendons, they usually glide smoothly through a covering called a tendon sheath. But when the tendon sheath gets swollen, the gliding isn’t so smooth and movement of your thumb and wrist becomes painful. In general, this condition is called tenosynovitis, or tendinosis. Swiss surgeon Fritz de Quervain was the first to describe it in this location.

Repetitive gripping with your hand and bending of your wrist is thought to be the cause of de Quervain’s tenosynovitis. This can happen in racket sports, such as tennis or racquetball, golf, or any activity where you grip with your hand and bend your wrist over and over again, such as lifting a child. It also can occur from repetitive blows to the area, such as when bumping a volleyball with improper technique.