Tendons are tough, fibrous, cord-like tissue bands that connect muscle to bone or another structure, such as an eyeball. A tendon helps a bone or structure move. An inflamed tendon is called tendonitis.

In most cases, tendinitis results from repeated injuries, such as those to the wrist and ankle. A joint becomes sore, stiff, swollen and painful as a result. In some cases, tendinitis is named after sports that are associated with an increased risk of developing it. Among them are tennis elbow, golfer’s elbow, pitcher’s shoulder, swimmer’s shoulder, and jumper’s knee.

Diagnosis involves physical examination and imaging tests.