Nephrology is a specialty of medicine and pediatrics that concerns itself with the kidneys: the study of normal kidney function and kidney problems, the preservation of kidney health, and the treatment of kidney problems, from diet and medication to renal replacement therapy (dialysis and kidney transplantation). Systemic conditions that affect the kidneys (such as diabetes and autoimmune disease) and systemic problems that occur as a result of kidney problems (such as renal osteodystrophy and hypertension) are also studied in nephrology. A physician who has undertaken additional training to become an expert in nephrology may call themselves a nephrologist or renal physician.

Nephrology concerns the diagnosis and treatment of kidney diseases, including electrolyte disturbances and hypertension, and the care of those requiring renal replacement therapy, including dialysis and renal transplant patients. Many diseases affecting the kidney are systemic disorders not limited to the organ itself, and may require special treatment.