Potatoes are subject to various disorders that are not caused by diseases, insects, or other pests. These are commonly referred to as physiological disorders and are usually the result either of an environmental factor causing abnormal growth patterns, or of biochemical events. This chapter discusses the most common physiological disorders. Growth cracks are splits in the tuber surface which usually penetrate through the cortex and into the perimedullary tissue. Brown center is manifested as a group of brown cells found in the pith or central area of the tuber. Hollow heart is a cavity or series of cavities found in the center of the tuber and may be located at one or more locations along the length of the tuber. Lenticels are the pores in the skin through which gas exchange is maintained by potato tubers. Elephant hide is identified by the rough irregular surface and thick periderm on portions of the affected tuber.