Nephrology

Nephrology is a clinical specialty within both adult internal medicine and paediatric medicine that focuses on the study of the kidneys, including their normal physiology, disorders affecting them, and the preservation of kidney health. It encompasses conditions ranging from electrolyte abnormalities and hypertension to advanced kidney failure requiring dialysis or transplantation. The adjective renal, derived from late Latin and French, refers to anything relating to the kidneys. Although some propose replacing terms such as renal and nephro- with kidney in scientific writing, many experts advocate preserving traditional terminology in contexts such as nephrology and renal replacement therapy.
The specialty also investigates systemic conditions that affect kidney function, including autoimmune diseases, diabetes, congenital disorders, and complications arising from chronic kidney disease such as renal osteodystrophy.

Etymology

The term nephrology originates from the Greek nephros (kidney) and was introduced in modern usage in the mid-twentieth century. French physician Jean Hamburger proposed the term néphrologie in 1953, and it came into broader use around 1960. Prior to this, the field was commonly referred to as “kidney medicine.”

Scope of the Specialty

Nephrology addresses the diagnosis and management of a broad spectrum of kidney-related conditions, which may include:

• Acute kidney injury and chronic kidney disease,
• Hematuria and proteinuria,
• Renal stone disease,
• Hypertension, and
• Disorders of acid–base balance and electrolytes.

A major area of practice involves providing and supervising renal replacement therapy, which includes both kidney dialysis and kidney transplantation. The word dialysis, derived from Greek roots meaning “to separate,” refers to the process of removing excess water and toxins from the blood when the kidneys can no longer perform this function effectively.
Many kidney diseases are manifestations of systemic disorders such as lupus erythematosus, vasculitis, congenital nephrotic syndrome, or polycystic kidney disease, and thus require specialised management.

The Nephrologist

A nephrologist is a physician with additional specialised training in kidney medicine. Although focused on renal disease, nephrologists often contribute to broader medical areas such as immunosuppression, organ transplantation, clinical pharmacology, perioperative medicine, intensive care, and paediatric nephrology.
Subspecialty areas within nephrology may include:

• Dialysis medicine,
• Transplant nephrology,
• Home dialysis therapies,
• Cancer-related kidney disorders (onconephrology),
• Structural kidney disease (uronephrology),
• Procedural nephrology,
• Fluid and haemodynamic management, and
• Bone and mineral disorders associated with chronic kidney disease.

Nephrologists may perform procedures such as kidney biopsies, vascular access insertion, peritoneal dialysis catheter placement, fistula evaluation and repair, and angiographic assessment of dialysis access.

Training Pathways

India

Training begins with the MBBS degree, followed by a three-year postgraduate qualification in internal medicine or paediatrics (MD or DNB). A further three-year specialised programme in nephrology or paediatric nephrology leads to certification as a nephrologist.

Australia and New Zealand

Training involves a medical degree (4–6 years), a one-year internship, at least three years of basic physician training, examinations by the Royal Australasian College of Physicians, and three years of advanced training in nephrology. Many trainees undertake additional research degrees such as a PhD. Ongoing professional development is common within specialist societies.

United Kingdom

In the UK, nephrology—often called renal medicine—is a subspecialty of internal medicine. Training includes medical school, foundation years, core medical training, Membership of the Royal College of Physicians, and competitive entry into a five-year specialty programme. Completion leads to a Certificate of Completion of Training and entry onto the GMC Specialist Register. Many trainees undertake research towards MD or PhD degrees.

United States

Two main pathways exist:

• Adult nephrology, following a three-year internal medicine residency and a two-year (or longer) nephrology fellowship.
• Paediatric nephrology, following paediatric training or combined internal medicine–paediatrics programmes, and a three-year paediatric nephrology fellowship.

Certification is awarded through the American Board of Internal Medicine or the American Osteopathic Board of Internal Medicine. Training covers dialysis modalities, haemofiltration, and, in some programmes, plasmapheresis.

Diagnostic Approaches

Diagnosis in nephrology rests on a detailed history and physical examination, focusing on symptoms, family history, medications, diet, occupational exposures, and systemic conditions. Physical assessment emphasises blood pressure, volume status, cardiovascular examination, and inspection for signs of autoimmune or systemic disease.
Urinalysis is central to detection of kidney abnormalities, including haematuria, proteinuria, pyuria, and abnormal casts or cells. While 24-hour urine collections were once routine, spot urine samples are now widely used to assess protein loss.
Blood tests used in nephrology may include measurements of:

• Creatinine and urea,
• Electrolytes (sodium, potassium, chloride, bicarbonate),
• Calcium, phosphate, magnesium,
• Albumin and alkaline phosphatase,
• Parathyroid hormone levels, and
• Full blood count parameters.

Serum creatinine is especially important, as it enables estimation of the glomerular filtration rate (GFR), a key indicator of kidney function.
Nephrologists also utilise imaging studies, renal biopsies, and vascular assessments where appropriate. In long-term kidney disease, monitoring blood pressure, proteinuria, and kidney function trends assists with treatment planning and disease progression control.