Causes

Chronic overuse of your wrist is commonly associated with de Quervain's tenosynovitis.

Tendons are rope-like structures that attach muscle to bone. When you grip, grasp, clench, pinch or wring anything in your hand, two tendons in your wrist and lower thumb normally glide smoothly through the small tunnel that connects them to the base of the thumb. Repeating a particular motion day after day may irritate the sheath around the two tendons, causing thickening and swelling that restricts their movement.

Other causes of de Quervain's tenosynovitis include:

• Direct injury to your wrist or tendon; scar tissue can restrict movement of the tendons
• Inflammatory arthritis, such as rheumatoid arthritis