Haglund's deformity is an abnormality of the bone and soft tissues in the foot.
An enlargement of the bony section of the heel (where the Achilles tendon is inserted) triggers this condition.
The soft tissue near the back of the heel can become irritated when the large, bony lump rubs against rigid shoes.
[2] The etiology is not well known, but some probable causes like a tight Achilles tendon, a high arch of the foot, and heredity have been suggested as causes.
Clinical evaluation and lateral radiographs of the ankle are mostly enough to make a diagnosis of Haglund's syndrome.