When the sensitive skin on the bottom of the feet and heels becomes too dry, it can split open, leaving painful cracks called fissures on your heels. Those cracks may not only make it painful to walk but can also lead to serious infections. Cracks in the heels are generally caused by insufficient moisture. These cracks can become sore and may even bleed. It can be treat by using a combination of a scalpel, filing, and topical treatment.