Achilles paratenonitis is inflammation of the covering of the Achilles tendon, which connects the calf muscles to the heel bone. It can cause scarring that restricts the motion of the Achilles tendon.

Achilles paratenonitis is caused by overuse or repeated movements and poorly fitted shoes. It is frequently seen in marathon runners. Symptoms include tenderness, pain, and swelling in the Achilles area. Symptoms are usually worse during activity.

Treatment consists of rest, pain relief, stretching exercises, and changes in sports techniques and footwear to reduce stress on the tendon.

Achilles paratenonitis is also known as Achilles peritendinitis, tenosynovitis, or tenovaginitis.