It is a very common foot problem. The sufferer usually feels pain either under the heel (plantar fasciitis) or just behind it (Achilles tendinitis), where the Achilles tendon connects to the heel bone. Even though heel pain can be severe and sometimes disabling, it is rarely a health threat. Heel pain is typically mild and usually disappears on its own; however, in some cases the pain may persist and become chronic (long-term). There are 26 bones in the human foot, of which the heel (calcaneus) is the largest. The human heel is designed to provide a rigid support for the weight of the body. When we are walking or running it absorbs the impact of the foot when it hits the ground, and springs us forward into our next stride. Experts say that the stress placed on a foot when walking may be 1.25 times our body weight, and 2.75 times when running. Consequently, the heel is vulnerable to damage, and ultimately pain. In the majority of cases, heel pain has a mechanical cause. It may also be caused by arthritis, infection, an autoimmune problem trauma, a neurological problem, or some other systemic condition (a condition that affects the whole body).