Nephrologists, or kidney doctors, study the kidneys and any diseases that affect them. They complete 2 more years of training after medical school and residency. If your primary care or family doctor thinks your kidneys aren’t working well, they may send you to a nephrologist. They’ll look for the cause of the problem and come up with a treatment plan that slows or stops it. You might need a referral from your regular doctor for insurance to cover the cost of your visit. Some of the diseases nephrologists treat are: Kidney disease. This is when your kidneys are damaged over time. You might not have severe symptoms until the disease is more advanced. But if your doctor catches it early, medications and lifestyle changes may help you avoid more damage. Kidney failure. This is the late stage of kidney disease. If your nephrologist recommends dialysis (which cleans your blood with a machine), they’ll be in charge of your care. They may also suggest a kidney transplant. This is typically handled by a different team and a nephrologist who specializes in transplants. You’ll probably keep seeing this person until your transplant and after.