Complex sentence: A nephrologist is a physician (MD, MBBS or DO) who has been trained in the diagnosis and management of kidney disease, by regulating blood pressure, regulating electrolytes, balancing fluids in the body, and administering dialysis.
Split into simpler sentences: A nephrologist is a medical doctor who has been trained in the diagnosis and management of kidney problems and their consequences on the body. This may be achieved by regulating blood pressure, regulating electrolytes, balancing fluids in the body, and administering dialysis.