De Quervain Tenosynovitis

De Quervain’s tenosynovitis is painful inflammation around your thumb tendons. It’s also called de Quervain’s tendinosis or de Quervain’s tendinitis. Healthcare providers sometimes use these names interchangeably to refer to the same condition.

Tendons link your muscles to your bones. They’re cords of strong, flexible tissue, similar to a rope. When you contract (squeeze) a muscle, tendons pull the bones they’re attached to and make them move. Two tendons connect your thumb to your wrist.

Usually, tendons slide easily through a tunnel of tissue called a sheath. De Quervain’s tenosynovitis happens when something makes the sheath around your thumb tendons swell or thicken. This swelling causes extra friction when you use your thumb and wrist. When this happens, certain thumb and wrist motions are painful and more difficult. De Quervain’s tenosynovitis usually causes pain near the base of your thumb that can extend (radiate) into your forearm.

How common is de Quervain’s tenosynovitis?

De Quervain’s tenosynovitis is one of the most common forms of tenosynovitis. Experts estimate that it affects around 1% of people in the U.S. each year.