Nephrologists are medical doctors who specialize in the diagnosis and treatment of diseases of the kidney and urinary system, such as inflammation of the kidneys, chronic kidney disease, or cancer.

Nephrologists may further specialize in treating certain age groups, such as pediatric nephrologists, who only treat children. Nephrologists may consult with people for short-term illnesses or procedures, such as for a kidney biopsy, or they may serve as a primary doctor for people who have long-term (chronic) kidney problems or who are on dialysis.

Nephrologists can be board-certified in nephrology through the Board of Internal Medicine, which is recognized by the American Board of Medical Specialties.