What Is a Nephrologist?
(And What to Expect at Your First Visit)

Most people don't know what a nephrologist is until their doctor sends them to one. Yet kidney disease affects approximately 1 in 7 American adults — the majority of whom have no idea until a routine blood or urine test flags a problem. Understanding what is a nephrologist before your first appointment makes the visit less intimidating and far more productive: a nephrologist is a kidney specialist who manages conditions ranging from high blood pressure with a kidney component to chronic kidney disease, dialysis, and beyond.

A referral to nephrology doesn't mean kidney failure is imminent or that you'll need dialysis. It means your primary care provider saw something that warrants a specialist's evaluation — and catching it early is exactly when nephrology care does the most good. This guide walks through what nephrologists do, why patients get referred, and how to prepare for your first visit so you leave with clarity instead of more questions.

A nephrologist is a physician who specializes in the kidneys — their function, their diseases, and the complications that arise when they don't work properly. The word comes from the Greek nephros (kidney) and is sometimes used interchangeably with "kidney doctor," though the specialty is far broader than the name implies.

A common point of confusion: nephrologist vs urologist. Urologists treat structural and surgical conditions of the urinary tract — kidney stones that need to be removed, bladder cancer, prostate conditions, and similar issues that may require procedures or surgery. Nephrologists are internists who focus on the medical management of kidney function — lab values, filtration rates, blood pressure regulation, and fluid and electrolyte balance. If you have a kidney stone, you might see both: a urologist to remove it and a nephrologist to evaluate whether it signals an underlying kidney disease.

Conditions a nephrologist treats include:

• Chronic Kidney Disease (CKD) — the gradual loss of kidney function over time, often caused by diabetes or high blood pressure
• High blood pressure with a kidney component — hypertension that damages the kidneys or is caused by kidney dysfunction
• Kidney stones — when stones reflect metabolic or filtration abnormalities that need medical management beyond removal
• Dialysis management — nephrologists oversee both hemodialysis and peritoneal dialysis for patients with end-stage kidney disease
• Electrolyte disorders — abnormal sodium, potassium, calcium, or phosphorus levels that the kidneys regulate
• Glomerulonephritis — inflammation of the kidney's filtering units, often autoimmune in origin

Why Would You Be Referred to a Nephrologist?

Most nephrology referrals originate from something abnormal in routine bloodwork or urinalysis. The five most common triggers are:

1. Abnormal Kidney Function on Bloodwork

Elevated creatinine, a low eGFR (estimated glomerular filtration rate), or a high BUN (blood urea nitrogen) are the most common reasons primary care doctors refer patients to nephrology. These markers reflect how well the kidneys are filtering waste — when they're outside the normal range, a nephrologist can determine whether the change is acute, chronic, or a result of dehydration or medication.

2. Protein or Blood in the Urine

Proteinuria (protein in urine) or hematuria (blood in urine) can indicate that the kidneys' filtering units are damaged or inflamed. While some causes are benign, persistent abnormalities warrant specialist evaluation to rule out glomerulonephritis, diabetic nephropathy, or other kidney diseases.

3. High Blood Pressure Not Responding to Treatment

Resistant hypertension — blood pressure that remains elevated despite multiple medications — often has a kidney component. Nephrologists evaluate whether the kidneys are contributing to the hypertension or being damaged by it, and adjust treatment accordingly.

4. Kidney Stones Requiring Specialist Management

Recurrent kidney stones, stones caused by metabolic abnormalities (high calcium, uric acid, or oxalate), or stones accompanied by declining kidney function may be referred to nephrology for underlying cause evaluation and prevention strategies.

5. Diabetes-Related Kidney Complications

Diabetic nephropathy is the leading cause of kidney failure in the United States. Patients with diabetes and declining kidney function, significant proteinuria, or rapidly dropping GFR are referred to nephrology for co-management and to slow disease progression.

What to Expect at Your First Nephrologist Visit

First nephrology appointments are structured around building a complete picture of your kidney function and medical history. Most visits follow this four-step flow.

Step 1 — Medical History and Kidney Function Review

Your nephrologist will spend significant time reviewing your medical history with a focus on anything that affects kidney health: diabetes, high blood pressure, prior kidney infections or stones, heart disease, medications (especially NSAIDs, certain antibiotics, and contrast dyes used in imaging), and family history of kidney disease. They'll also review all prior lab results — ideally going back as far as you have them — to understand whether kidney function has been declining gradually or changed suddenly.

Step 2 — Blood Pressure and Physical Examination

Blood pressure measurement is central to every nephrology visit — high blood pressure both causes and worsens kidney disease. Your nephrologist will assess your blood pressure carefully, often taking multiple readings. The physical exam focuses on signs of fluid retention (swelling in the legs or ankles), cardiovascular health, and any signs of complications from kidney disease such as pallor or changes in skin tone.

Step 3 — Additional Lab Work and Urine Tests

Expect new bloodwork and urine testing at or shortly after your first appointment. Common orders include a comprehensive metabolic panel, a repeat GFR and creatinine, a urine albumin-to-creatinine ratio (to quantify protein loss), a complete urinalysis with microscopy, and a 24-hour urine collection in some cases. These results give your nephrologist a current baseline and help confirm or rule out the reasons for your referral. Ask which tests require fasting and whether you need any special preparation.

Step 4 — Diagnosis Discussion and Treatment Plan

If your prior labs are sufficient and the diagnosis is clear, your nephrologist may share an initial plan at the end of the first visit — which might include medication adjustments, dietary changes, or lifestyle recommendations. More often, they'll wait for new test results before making definitive recommendations. Either way, make sure you leave knowing: what tests were ordered, what the working hypothesis is, and when and how you'll receive results and next steps.

Questions to Ask Your Nephrologist on Your First Visit

Knowing which questions to ask your nephrologist on your first visit can be the difference between leaving with a clear plan and leaving confused about what comes next. For a broader question framework, see our guide on questions to ask your doctor. The nephrology-specific questions below are organized by category.

How to Prepare for Your First Nephrologist Visit

Nephrology appointments are data-heavy — your provider will be reviewing lab trends, medication lists, and blood pressure history. Coming organized makes the appointment more efficient and more useful. Start with our guide on how to prepare for a doctor's appointment for the general framework, then add the nephrology-specific steps below.

The National Kidney Foundation's guide on your first visit with a kidney doctor recommends bringing as much prior lab history as possible — kidney function trends over time are often more telling than a single result.

Key preparation steps:

• Pull all prior lab results — especially creatinine, BUN, and eGFR values. If you've had these tested before, bring results going back as far as you have them. Trends matter more than single values.
• Compile your complete medication list — including supplements, vitamins, and any OTC pain relievers. NSAIDs (ibuprofen, naproxen), certain supplements, and contrast dyes can all affect kidney function and must be disclosed.
• Log your blood pressure — if you have a home blood pressure cuff, bring 1–2 weeks of readings. If you don't have one, note any readings from pharmacy kiosks or prior appointments.
• Bring urine test results — if your referral was triggered by protein or blood in the urine, bring those specific results.
• Document your family history — kidney disease, polycystic kidney disease (PKD), dialysis, or kidney transplant in close relatives are all relevant.
• Check fluid and fasting instructions — call the office when scheduling to ask whether you should fast before any ordered labs.

VisitReady is a free Android app that generates your personalized question list and visit summary automatically — so you walk in with everything organized and nothing forgotten.

What to Bring to Your First Nephrologist Visit

Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for guidance specific to your health situation.