Nephrology is the adult and pediatric study of the kidneys and its diseases. The nephrologist deals with the diagnosis and management of kidney disease. The kidneys are vital for maintaining normal fluid and electrolyte balance in the body. Nephrology is a specialty of adult internal medicine and pediatric medicine that concerns the study of the kidneys, specifically normal kidney function and kidney disease, the preservation of kidney health, and the treatment of kidney disease, from diet and medication to renal replacement therapy