Q: I keep getting a painful red bump on the back of my heel bone. It's an area that rubs against my shoe, especially when I wear flat dress shoes. What is it?
A: The redness and pain may be a sign of bursitis, which is inflammation of a bursa - a bursa is a normal anatomical feature that is meant to reduce friction, such as in areas between tendon and bone. Bursitis can be associated with excessive stress on the Achilles tendon (see: retrocalcaneal bursitis). However, bursitis can develop over the back of the heel bone (calcaneus) from rubbing against the shoe, especially if that part of the bone is prominent. This is known as Haglund's deformity, which is sometimes called by its less formal name, a pump bump.
Wearing dress shoes may contribute to the problem by increasing friction against the back of the heel. Some styles of dress shoes, whether they are flat or have a heel, lack the support needed to keep the foot securely in the shoe. Wearing the wrong size shoe is also a possible cause. Since there are quite a few causes of heel pain, a visit to a podiatrist or foot specialist would be best.