Tenosynovitis (ten-o-sin-o-VITE-is) is irritation and swelling of the lining, or casing, that covers a tendon.

More to Know

Tendons are cords that attach muscles to bones. Each tendon is covered by a casing, or sheath, called the tenosynovium. The tenosynovium protects and lubricates the tendon, allowing it to move more easily when a muscle is flexed or extended.

Tenosynovitis happens when the tenosynovium becomes irritated and swollen. This can be caused by certain diseases, infections, injuries, overuse, or strain. Tenosynovitis can affect any tendon in the body, but is most common in the hands, wrists, and feet.

To treat it, doctors might recommend resting the affected tendon and using a splint or brace to keep the tendon from moving. Tenosynovitis caused by an infection is considered an emergency, is treated with antibiotics, and may need surgery.

Keep in Mind

Symptoms such as joint pain, swelling, redness, and difficulty moving a joint should be evaluated by a doctor immediately. In most cases, tenosynovitis heals completely with rest and treatment.

Following recovery, strengthening and stretching exercises might be recommended. It also can be helpful to decrease or stop activities that irritate the affected tendon.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.