Cracks in the skin around the heel are common, are uncomfortable, and don't look very good. They happen if the fat pad under the heel stretches out sideways under the heel bone and the dried-out skin cracks or splits to create a heel fissure. A great way to fully understand these is to use the analogy of a tomato being compressed. When you apply force to the tomato to squash it, the skin around the tomato splits as the insides forces outwards. So it is with the heel. As bodyweight squashes the fat under the heel it stretches out sideways from under the heel, it tries to tear the skin around the perimeter of the heel. Whether or not it succeeds or not will probably depend on how elastic and resilient that the skin is. If the skin is dry, thicker or callused, it is going to split easily. If the skin is thicker with a layer of callus, that skin will split easily and place a strain on the good skin below that could become somewhat painful, perhaps bleeding. Every step which is taken with further open the fissure and prevent it from healing. Cracked heels are more prevalent in people who wear open heel type shoes, as a closed in shoe will help keep the fat pad beneath the heel in place and help stop or decrease the effects of this.
The most efficient short term relief of cracked heels is to have the thick skin removed by a podiatrist and then use tape to hold the sides of the split together so that it can heal. The long term prevention of cracked skin around the heel ought to be apparent from the mechanism that was described above. To start with, losing weight will help decrease the problem, but this is a long term issue. To help stop the fat pad beneath the heel from broadening out sideways and trying to crack the skin, a closed in shoe can be used and in some cases the use of deep heel cup inserts will help. A foot doctor should really be consulted routinely to cut back any dry callused skin. Emollients should be applied regularly to keep the skin resilient so that it does not split. The use of pedicure files to help keep the thick skin under control may also be used. Often a visit to a podiatrist will set the selfcare plan off to a good start.