Thick and hard heel skin may be caused by physiological reasons such as long-term wear and tear, or may be caused by pathological factors such as infection. 1. Physiological reasons: the plantar part of the foot is at the bottom of the body, long-term walking activities or thin soles may lead to the heel part of the long-term repeated friction stimulation, resulting in excessive keratinization of the local skin of the heel, resulting in thick and hard heel skin. 2. Pathological factors: the heel area secondary to anaerobic bacteria infection and tinea pedis, due to the characteristics of anaerobic bacteria itself will also cause excessive keratinization of the heel area, appearing in the heel area of the stratum corneum of the diffuse thickening, roughness, hardness and so on. Based on the symptoms of thick and hard heel skin alone, it is sometimes impossible to accurately determine the cause, but also need to be combined with the characteristics of the medical history, other test results to make an accurate judgment, it is recommended to clarify the cause of the disease under the guidance of a doctor.