The fifth edition of Clinical Physiology of Acid-Base and Electrolyte Disorders has been largely rewritten to include the many important advances that have been made and the controversies that have arisen in the past six years. As with the previous four editions, this book attempts to integrate the essentials of renal and electrolyte physiology with the common clinical disorders of acid-base and electrolyte balance. Its underlying premise is that these clinical disturbances can be best approached from an understanding of basic physiologic principles. Thus, Chapters 1,2,3,4,5,6 review the physiology of normal renal function and the effects of hormones on the kidney. This is followed by a discussion of the extrarenal and renal factors involved in the internal distribution of the body water and in the normal regulation of volume (sodium), water, acid-base, and potassium balance (Chapters 7,8,9,10,11,12). In addition to providing the foundation for understanding how disease states can overcome these regulatory processes, the initial chapters can also be used by first-year medical students studying renal physiology.