A pump bump is an enlarged section of bone found at the back of the heel bone and is a painful issue commonly faced by runners. It can be quite troublesome to address. The larger portion of the heel bone rubs against footwear, leading to pain and lesions. This bursitis may be rather swollen. https://runningone.net/how-to-deal-with-a-bony-bump-at-the-back-of-the-heel/