An injury of the Achilles tendon, which joins the calf muscles to the heel bone.

Achilles tendinitis is an injury of the Achilles tendon often caused by overuse. The Achilles tendon is a band of tissue that joins the calf muscle at the back of the lower leg to the heel bone. Achilles tendinitis is common in runners and middle-aged people who play sports only on the weekends.

Treatment most often does well with self-care. Exercises can heal, stretch and strengthen the Achilles tendon. Tendon tears may need surgery.

Achilles tendinitis pain most often begins as a mild ache in the back of the leg or above the heel after running or other sports activity. More-severe burning or aching pain might occur after running a long time, stair climbing or sprinting.