Bursitis is painful inflammation of a bursa (a flat, fluid-filled sac that provides cushioning and reduces friction in areas where skin, muscles, tendons, and ligaments rub over bones). Bursitis can develop at the bottom of the heel (the calcaneus).
(See also Overview of Foot Problems Overview of Foot Problems Some foot problems start in the foot itself, for example, resulting from a foot injury. Problems can occur in any bone, joint, muscle, tendon, or ligament of the foot. Foot and ankle fractures... read more 
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The heel may throb, particularly when the shoes are removed, and may be slightly warm and swollen. The pain is worst when the heel first contacts the ground during walking or running.
The diagnosis of inferior calcaneal bursitis is based on a person’s symptoms and examination findings.
Doctors treat inferior calcaneal bursitis by injecting an anesthetic/corticosteroid mixture into the bursa and advising the person to wear soft-soled shoes with added protective heel cushion padding.
