Where the tendon joins the calcaneal bone, friction can cause the spaces between the tendon, bone and skin to swell and inflame with bursitis. This constitutes a calcaneal bursa. Apart from swelling over the back of the heel, you’ll feel acute tenderness and pain when you move it or even apply light pressure.
Your swollen heel may look more red than the other one, and the swelling is often so hard it can feel like bone – partly because it sometimes is, as a bony overgrowth can occur in chronic cases.
Probably unnecessary, except to exclude differential diagnoses.
Both stress and complete fractures equal a calcaneal bursa in intensity and pain, so must be eliminated by x-ray or scan.
If you avoid pressure you will ease the pain, so bigger shoes, soft padding, or avoiding heel backs by using sandals or running without shoes can help. Non-steroidal anti-inflammatory tablets and ice are the other staple treatments.
If physio and self-administered therapy fail, a cortisone injection into the bursa may deflate it, although surgery to remove the bursa and excess bone may be the final solution.
Can you run through it?
With pain, runners sometimes do, but probably at the expense of worsening the bursa.
After surgery, the usual rehabilitation and training downgrade mean that racing will be three to six months away.