A heel spur is a growth that occurs where the plantar fascis attaches to the heel, more frequent in women, attributed to wearing high heeled shoes.
Heel spurs are a secondary symptom of plantar fasciitis which is the fibrous band that runs along the bottom of the foot and maintains the arch. As the plantar fascia is stressed and starts to pull away from the heel, the body tries to repair the injury by filling in the gap with bone. This may begin as a dull pain in the heel, and sometimes in the mid or fore foot. Pain is usually worse after getting out of bed or a prolonged period of rest.