A condition in which the tissue connecting muscle to bone becomes irritated and swollen, called inflamed.

Tendinitis is swelling and irritation of the thick cords that attach muscle to bone, called tendons. It can happen in any tendon, but it's most common around shoulders, elbows, wrists, knees and heels.

Symptoms tend to be where the tendon attaches to a bone. There might be a dull ache, mostly when moving the hurt limb or joint. Tenderness and mild swelling also may happen.

Self-care, including rest, ice and pain relievers, might be all that's needed. Full recovery might take several months. Physical therapy, steroid injections or other procedures might help.