Achilles tendinitis is a common condition that occurs when the large tendon that runs down the back of your lower leg becomes irritated and inflamed.
The Achilles tendon is the largest tendon in the body. It connects your calf muscles to your heel bone and is used when you walk, run, climb stairs, jump, and stand on your tip toes. Although the Achilles tendon can withstand great stresses from running and jumping, it is also prone to tendinitis, a condition associated with overuse and degeneration.
Simply defined, tendinitis is inflammation of a tendon. Inflammation is the body’s natural response to injury or disease, and often causes swelling, pain, or irritation.
There are two types of Achilles tendinitis, based upon which part of the tendon is inflamed.
In noninsertional Achilles tendinitis, fibers in the middle portion of the tendon have begun to break down with tiny tears (degenerate), swell, and thicken.
Tendinitis of the middle portion of the tendon more commonly affects younger, active people.
Insertional Achilles tendinitis involves the lower portion of the heel, where the tendon attaches (inserts) to the heel bone.
In both noninsertional and insertional Achilles tendinitis, damaged tendon fibers may also calcify (harden). Bone spurs (extra bone growth) often form with insertional Achilles tendinitis.
Tendinitis that affects the insertion of the tendon can occur at any time, even in patients who are not active. More often than not, however, it comes from years of overuse (long distance runners, sprinters).
Achilles tendinitis is typically not related to a specific injury. The problem results from repetitive stress to the tendon. This often happens when we push our bodies to do too much, too soon, but other factors can make it more likely to develop tendinitis, including:
Common symptoms of Achilles tendinitis include:
If you have experienced a sudden “pop” in the back of your calf or heel, you may have ruptured (torn) your Achilles tendon. See your doctor immediately if you think you may have torn your tendon.
After you describe your symptoms and discuss your concerns, the doctor will examine your foot and ankle. The doctor will look for these signs:
Your doctor may order imaging tests to make sure your symptoms are caused by Achilles tendinitis.
X-ray tests provide clear images of bones. X-rays can show whether the lower part of the Achilles tendon has calcified, or become hardened. This calcification indicates insertional Achilles tendinitis. In cases of severe noninsertional Achilles tendinitis, there can be calcification in the middle portion of the tendon, as well.
Although magnetic resonance imaging (MRI) is not necessary to diagnose Achilles tendinitis, it is important for planning surgery. An MRI scan can show how severe the damage is in the tendon. If surgery is needed, your doctor will select the procedure based on the amount of tendon damage.