What Is a Nephrologist?

A Specialist Trained in Diseases of the Kidneys

A nephrologist is a doctor who specializes in kidney health and kidney disease. In medical practice, the term renal is used to describe anything involving, affecting, or located near the kidneys, so nephrologists are often referred to as renal specialists.

Child's lower back diagnosis with ultrasound
endopack / Getty Images

Nephrology is a subspecialty of internal medicine. A nephrologist needs to complete internal medicine training before pursuing an additional fellowship in nephrology. According to the American Society of Nephrologists (ASN), there are just over 10,000 nephrologists actively practicing in the United States.

The term nephrology is derived from the Greek nephros meaning "kidneys" and the suffix -ology meaning "the study of."


Nephrology encompasses a wide range of medical disciplines, including:

  • The study of normal kidney function
  • The causes and diagnoses of kidney diseases
  • The treatment of acute or chronic kidney diseases
  • The preservation of kidney function
  • Kidney transplantation

Nephrology also involves treating systemic conditions that affect the kidneys (such as diabetes and autoimmune diseases) and systemic diseases that occur as a result of kidney disease (such as hypertension).

While it's possible that you may see a nephrologist in a hospital setting, you're more likely to see a nephrologist in a private practice or dialysis facility.


Nephrologists are typically called in when there are signs of kidney injury or disease. For instance, people are often referred to a nephrologist after a urinalysis picks up an abnormality, such as hematuria (blood in urine), proteinuria (excess protein in urine), or an imbalance of electrolytes or urinary pH. In other cases, overt symptoms of kidney disease may be seen.

Broadly speaking, kidney diseases can be classified as either acute or chronic:

  • Acute kidney injury (AKI) is the abrupt loss of kidney function that develops over a short period of time. The symptoms can vary by the underlying cause but may include the rapid onset of fatigue, loss of appetite, headache, nausea, vomiting, increased thirst, abnormal heart rhythms, flank pain, and rash. This illness is of short duration, rapidly progressive, and in need of urgent care.
  • Chronic kidney disease (CKD) is characterized by the gradual loss of kidney function over a period of months or years. Early on, there may be no symptoms. Later, fatigue, edema (leg swelling), muscle cramps, vomiting, loss of appetite, persistent itching, chest pains, shortness of breath, or confusion may develop.

Conditions Treated

Nephrologists are generally focused on primary kidney disorders—that is, those originating in these important organs.

Although the prevention and management of early kidney disease are within the scope of nephrology practice, nephrologists are usually called upon to assist with more complex or advanced renal disorders.

These may include:

  • Amyloidosis, the buildup of abnormal proteins, called amyloids, in various organs of the body (including the kidneys)
  • Congenital kidney malformations
  • Diabetic nephropathy, the number one cause of kidney disease
  • Glomerulonephritis, a disease that affects tiny units in the kidneys, called glomeruli, where blood is cleaned
  • Lupus nephritis, inflammation of the kidneys caused by the autoimmune disease lupus
  • Nephrotic syndrome, a disorder that causes your body to excrete too much protein in your urine
  • Polycystic kidney disease, a genetic disorder in which clusters of cysts develop within the kidneys
  • Pyelonephritis, a type of urinary tract infection where one or both kidneys become infected
  • Renal failure, in which the kidneys fail to adequately filter waste products from the blood
  • Renal obstruction, caused by kidney stones, tumors, an enlarged prostate, and other conditions
  • Renal stenosis, the narrowing of arteries to the kidney, typically linked to chronic hypertension

Procedural Expertise

A nephrologist is qualified to provide all facets of treatment of kidney disease, either primary or secondary. This may involve medications (including ACE inhibitors, statins, diuretics, or calcium and vitamin D supplements) and management of lifestyle factors (including diet, smoking, and weight loss).

Nephrologists can also perform, oversee, or assist in other procedures to either manage or treat kidney disorders.

These include:

  • Percutaneous needle biopsy: The insertion of a needle through the abdomen to obtain kidney specimens
  • Kidney ultrasonography: Using ultrasound to help monitor a disease or guide certain medical procedures
  • Bone biopsy to monitor and manage bone disorders associated with kidney cancer or CKD
  • Kidney dialysis, including hemodialysis, peritoneal dialysis, and continuous renal replacement therapy
  • Kidney transplants


Some nephrologists specialize in a narrower field of practice. These typically involve additional training and research fellowships.

Among some of the most common nephrology subspecialties are:

  • Critical care nephrology
  • Kidney dialysis (including arteriovenous fistula surgery)
  • Interventional nephrology (involving ultrasound-guided procedures)
  • Onconephrology (involving cancer-related kidney diseases)
  • Pediatric nephrology
  • Kidney transplantation

Training and Certification

A physician can specialize in nephrology through two different educational paths. In both cases, they would first complete medical school as a doctor of medicine (MD) or doctor of osteopathic medicine (DO) and then spend at least five years in specialty training.

  • To specialize in adult nephrology, the doctor would complete a three-year residency in internal medicine and then a fellowship in nephrology of at least two years.
  • To specialize in pediatric nephrology, a doctor would complete either a three-year pediatric residency or a four-year combined internal medicine/pediatrics residency, followed by a three-year fellowship in pediatric nephrology.

After the completion of training, the doctor is eligible to take the board exam and be certified in nephrology by either the American Board of Internal Medicine (ABIM) or the American Osteopathic Board of Internal Medicine (AOBIM). Some nephrologists continue with additional fellowships in nephrology subspecialties.

Appointment Tips

When searching for a nephrologist, do not hesitate to ask for several referrals, either from your general practitioner or health insurer. Before making your first appointment, be sure that the office accepts your insurance coverage. If you are not insured, ask if they offer a payment plan.

Although there are only two certifying bodies for nephrologists in the United States, only the ABIM allows you to check their certification online through their verification website. The credentials of non-ABIM nephrologists can often be confirmed through the non-profit Certification Matters website offered by the American Board of Medical Specialties (ABMS).

Alternately, don't be afraid to ask the doctor to provide you with their credentials. You can then conduct your own search through the state licensing board.

When meeting with a nephrologist for the first time, ask a few questions to better understand your condition and what may be involved.

For example, you might ask:

  • Why was I referred to see you?
  • Why are my kidneys not functioning as they're supposed to?
  • What is the current state of my kidneys?
  • How rapidly is my kidney function declining?
  • What can I do to slow or reverse this?
  • What are my options for treatment?
  • What will happen if I choose not to be treated?
  • Who and when should I call if I have any problems?

A Word From Verywell

It's important that you feel comfortable with your doctor and that you are satisfied with your interactions. If you want a referral to a different nephrologist or nephrology clinic, talk to your primary care provider and ask them for a different recommendation.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Salsberg E, Quigley L, Mehfoud N, Masselink L, Collins A. The US Adult Nephrology Workforce 2016: Developments and Trends. Washington, DC: American Society of Nephrologists; 2016.

  2. Quigley L, Salsberg E, Collins A. Report on the Survey of 2018 Nephrology Fellows. Washington, DC: American Society of Nephrologists, 2018.

By Andrea Clement Santiago
Andrea Clement Santiago is a medical staffing expert and communications executive. She's a writer with a background in healthcare recruiting.