Achilles tendinosis is a common problem of the Achilles tendon. Unfortunately, many patients and doctors alike confuse the term Achilles tendonitis with Achilles tendinosis. Achilles tendinosis is a chronic problem that is characterized by microscopic tears of the Achilles tendon. On the other hand, Achilles tendonitis occurs when there is acute (sudden onset) inflammation of the tendon. Distinguishing these conditions is important to ensure proper treatment. Achilles tendinosis, on the other hand, is a separate condition and is not characterized by inflammation. Instead, these patients experience thickening of the tendon. There is typically no warmth or redness surrounding the soft tissues, although the patient may experience pain. Achilles tendinosis is known as a chronic problem. This means that it is a long-term condition that develops over time. Inflammatory cells would not be seen on a microscopic level with this condition. However, very small tears of the tendon may be seen along with chronic damage. The symptoms of Achilles tendinosis are the best way to make the diagnosis of this condition. Typically an X-ray of the ankle joint will be normal, although it is possible to see small calcific deposits or bone spurs around the tendon, these are signs of chronic inflammation. An MRI test can also be performed which may show the microscopic tearing or degeneration of the tendon tissue, as well as thickening of the damaged portion of the tendon.