This book is written for the primary care clinician to help update knowledge of pediatric nephrology. The current and future shortage of pediatric nephrologists necessitates steady, rejuvenated information on the Aristolean kidney for primary care clinicians, as they care for the child and adolescent with renal and genitourinary dilemmas and disorders. In view of this shortage and the rapidly increasing knowledge in pediatric nephrology, as well as understanding indications for referral to pediatric nephrologists in the t twenty-first century, au courant assiduous information aimed at primary care clinicians in these areas becomes increasingly important. Chapters in this book cover nephrological problems in different pediatric ages, including newborns. As noted by some of the ancient scholars, the kidney does not exist in isolation, but is involved in other aspects of the body. Thus, we include chapters on the kidney in metabolic and rheumatoid disorders. Behavioral aspects of chronic disease, including renal disorders, are also considered because of the importance that renal (and chronic) disease has on the child and adolescent.