Heel fissures (cracked heels) are splits of the epidermis and stratum corneum that occur in many individuals as a consequence of excessive dryness (xerosis) and thickening of the skin. Heel fissures also develop in callused skin. Skin fissures are especially common in winter, when dry cold air is made even drier by indoor heating. The elderly population is at particular risk. In some people, heel fissures occur year round. It should be noted that air conditioning not only cools the air but dries it as well. Because of this, "winter itch" and dryness can even occur in the summer.

People with atopic dermatitis are at higher risk for heel fissures. Other risk factors that may predispose to this condition include obesity, prolonged standing, and wearing open-backed shoes or sandals. Heel fissures can be very uncomfortable and are often painful. Rarely, fissures can provide a portal of entry for secondary bacterial infection. Heel fissures can also develop in other skin conditions such as juvenile plantar dermatosis, pityriasis rubra pilaris, and psoriasis. Heel fissures are of particular concern in individuals with diabetes, as they can lead to slowly healing ulcers and secondary infection.