De Quervain tenosynovitis (dih-kwer-VAIN ten-oh-sine-oh-VIE-tis) is a painful condition that affects the tendons on the thumb side of the wrist. If you have de Quervain tenosynovitis, you typically feel pain when you turn your wrist, grip something or make a fist.
The exact cause of de Quervain tenosynovitis isn't known. But activities that involve repeating the same hand or wrist movements can make the condition worse. For example, gardening, playing golf or racket sports, and lifting a baby can make it worse.
Symptoms of de Quervain tenosynovitis include:
If not treated, the pain may spread into the thumb, forearm or both. Moving the thumb or wrist may make the pain worse.
Talk to your healthcare professional if you're still having pain or trouble using your thumb after trying the following:
De Quervain tenosynovitis affects the two tendons on the thumb side of the wrist. Tendons are rope like tissues that connect muscles to bones.
Doing the same hand movements over and over — such as lifting, gripping or twisting — can irritate the protective covering around these tendons. When this covering is irritated, the tendons may swell and thicken. This makes it harder for them to slide smoothly through the small tunnel that connects them to the base of the thumb.
Other causes of de Quervain tenosynovitis include:

When you grip, grasp, clench, pinch or wring anything in your hand, two tendons in your wrist and lower thumb typically 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.
Risk factors for de Quervain tenosynovitis include:
If de Quervain tenosynovitis isn't treated, it can become hard to use your hand and wrist as you'd like. You may lose some range of motion in your wrist.