The Achilles tendon is a large tendon located in the back of your leg. It connects the calf muscles to an insertion along the back of the heel bone. It’s the strongest tendon in the body and allows people to push off while walking, running, and jumping.

Achilles tendinitis is an overuse injury that occurs most commonly in runners who have suddenly increased the intensity or duration of their runs. It's also common in middle-aged people who play sports, such as tennis or basketball, only on the weekends.

Most cases of Achilles tendinitis can be treated with relatively simple, at-home care under your doctor's supervision. Self-care strategies are usually necessary to prevent recurring episodes. More serious cases of Achilles tendinitis can lead to tendon tears (ruptures) that may require surgical repair.