The Ultimate and Complete Nephrology Comprehensive Exam Study Guide 2026,
Aligned With Current KDIGO Guidance and ABIM–ESENeph Nephrology Curriculum
Concepts, Covering Acute Kidney Injury and Acute Kidney Disease, Chronic Kidney
Disease Evaluation and Management, Glomerular Diseases, IgA Nephropathy, Lupus
Nephritis, ANCA-Associated Vasculitis, Diabetic Kidney Disease, Hypertension and
Kidney Disease, CKD-Mineral and Bone Disorder, Anemia of CKD, Electrolyte and Acid-
Base Disorders, Nephrotic and Nephritic Syndromes, Tubulointerstitial and Cystic
Kidney Diseases, Genetic Kidney Disorders, Kidney Replacement Therapy,
Hemodialysis and Peritoneal Dialysis, Kidney Transplantation, Nephrotoxic
Medications, Fluid and Volume Management, Renal Pharmacology, Pediatric and Adult
Nephrology, Critical Care Nephrology, Diagnostic Testing and Kidney Biopsy, Clinical
Decision-Making, Case-Based Questions, Practice Questions With Detailed Rationales,
and Comprehensive Board-Review Strategies
Question 1: A 68-year-old male with a history of hypertension and type 2 diabetes mellitus
presents with a serum creatinine of 2.8 mg/dL, up from 1.5 mg/dL six months ago. His
urinalysis shows 3+ proteinuria and no active sediment. A renal ultrasound reveals normal-
sized, echogenic kidneys. Which of the following is the most likely diagnosis?
A. Acute Interstitial Nephritis
B. Acute Tubular Necrosis
C. Diabetic Kidney Disease
D. Focal Segmental Glomerulosclerosis
CORRECT ANSWER: C. Diabetic Kidney Disease
Rationale: The patient's history of long-standing diabetes, progressive renal insufficiency, heavy
proteinuria, and normal-sized echogenic kidneys on ultrasound are classic features of diabetic
kidney disease (DKD). The lack of active sediment makes acute interstitial nephritis or acute
tubular necrosis less likely, as they are typically associated with pyuria or muddy brown casts,
respectively. While FSGS can present with nephrotic syndrome, the clinical context and gradual
rise in creatinine over six months strongly favor DKD.
Question 2: A 45-year-old female presents with acute-onset flank pain, nausea, and
microscopic hematuria. Her blood pressure is 155/95 mmHg. Urinalysis reveals dysmorphic
red blood cells and red blood cell casts. Which of the following is the most appropriate initial
diagnostic test to confirm the suspected diagnosis?
A. Computed Tomography Angiography (CTA)
B. Renal Biopsy
C. Urine Culture and Sensitivity
D. Serum Complement (C3, C4) Levels
,CORRECT ANSWER: A. Computed Tomography Angiography (CTA)
Rationale: The presentation of acute flank pain, hypertension, and hematuria with dysmorphic
RBCs and RBC casts is highly suggestive of a nephritic syndrome. While a renal biopsy is the gold
standard for glomerulonephritis, CTA is the most appropriate initial test to rule out renal artery
stenosis or thrombosis, which can present with similar symptoms, especially in a patient with
acute hypertension. CTA can also evaluate for other causes of acute flank pain. Serum
complement levels are useful for classifying glomerulonephritis but are not the initial diagnostic
step in this acute setting.
Question 3: A 72-year-old male with stage 4 chronic kidney disease (CKD) is started on
lisinopril for hypertension. One week later, his serum creatinine rises from 2.9 mg/dL to 3.7
mg/dL. Which of the following is the most appropriate next step in management?
A. Discontinue lisinopril immediately and start an ARB.
B. Increase the dose of lisinopril to achieve better blood pressure control.
C. Continue lisinopril and monitor renal function closely.
D. Obtain a renal ultrasound to assess for hydronephrosis.
CORRECT ANSWER: C. Continue lisinopril and monitor renal function closely.
Rationale: An acute rise in serum creatinine of up to 30% is an expected hemodynamic effect of
ACE inhibitors (like lisinopril) in patients with CKD, due to efferent arteriolar dilation. This rise is
usually benign and stabilizes within a few weeks. The medication should be continued as long
as the rise is not >30% from baseline and there are no signs of hyperkalemia or angioedema.
Discontinuing the drug would be premature, and increasing the dose is not indicated. A renal
ultrasound is unnecessary unless there is suspicion of obstruction, which is not suggested here.
Question 4: A 55-year-old male with a history of gout presents with severe pain in his right
great toe. His medications include allopurinol and hydrochlorothiazide. Laboratory studies
show a serum uric acid of 9.2 mg/dL and a creatinine of 1.3 mg/dL. Which of the following is
the most appropriate initial treatment for his acute gout flare?
A. Increase the dose of allopurinol.
B. Start colchicine.
C. Start probenecid.
D. Start febuxostat.
CORRECT ANSWER: B. Start colchicine.
Rationale: The patient is having an acute gout flare. Colchicine is a first-line agent for acute
flares, especially when initiated early. It is important not to start or increase urate-lowering
,therapy (like allopurinol) during an acute flare, as this can worsen the flare by causing a rapid
shift in uric acid levels. Probenecid is a uricosuric agent and is not used for acute flares.
Febuxostat is another urate-lowering agent and is not indicated for acute treatment. The
thiazide diuretic should be reviewed, but the immediate need is pain and inflammation control.
Question 5: A 68-year-old female with end-stage renal disease (ESRD) on hemodialysis
presents with a fever and chills. Her blood cultures are positive for Gram-positive cocci in
clusters. Which of the following is the most likely source of the infection?
A. Dialysis catheter
B. Urinary tract infection
C. Pneumonia
D. Infected arteriovenous fistula
CORRECT ANSWER: A. Dialysis catheter
Rationale: In patients on hemodialysis, the most common source of bacteremia, especially with
Gram-positive organisms like Staphylococcus aureus, is the vascular access device, particularly a
central venous catheter. While an infected AV fistula is possible, catheters have a significantly
higher infection rate. The other options are less common sources of bacteremia in this specific
patient population with a known vascular access device.
Question 6: A 50-year-old male with autosomal dominant polycystic kidney disease (ADPKD)
presents with sudden-onset, severe flank pain and gross hematuria. Which of the following is
the most likely cause of his symptoms?
A. Nephrolithiasis
B. Ruptured renal cyst
C. Renal infarction
D. Urinary tract infection
CORRECT ANSWER: B. Ruptured renal cyst
Rationale: Acute flank pain and gross hematuria in a patient with ADPKD are classic presenting
symptoms of a ruptured or hemorrhagic renal cyst. While nephrolithiasis and UTIs can occur,
cyst rupture is a well-known and common complication. Renal infarction is less common in
ADPKD. The suddenness and severity of the pain point toward a structural complication like a
cyst rupture.
, Question 7: A 60-year-old female with a history of recurrent UTIs is diagnosed with a left-
sided staghorn calculus. The stone is composed of struvite. Which of the following is the most
important component of the initial management strategy?
A. Extracorporeal shock wave lithotripsy (ESWL)
B. Complete stone removal via percutaneous nephrolithotomy (PCNL)
C. Antibiotic therapy based on urine culture and sensitivity
D. Dietary restriction of oxalate
CORRECT ANSWER: C. Antibiotic therapy based on urine culture and sensitivity
Rationale: Struvite (magnesium ammonium phosphate) stones are always associated with
urease-producing bacteria (most commonly Proteus). The most critical initial step is to identify
and treat the underlying infection with appropriate antibiotics. Complete stone removal with
PCNL is the definitive treatment for staghorn stones, but it should be done after a course of
antibiotics to reduce the risk of sepsis. ESWL is not effective for large staghorn calculi. Dietary
oxalate restriction is for calcium oxalate stones.
Question 8: A 42-year-old male with a history of hypertension is found to have a serum
potassium of 6.2 mEq/L. His ECG shows peaked T waves. Which of the following is the most
appropriate immediate treatment?
A. Oral sodium polystyrene sulfonate (Kayexalate)
B. Intravenous calcium gluconate
C. Intravenous insulin with dextrose
D. Intravenous sodium bicarbonate
CORRECT ANSWER: B. Intravenous calcium gluconate
Rationale: The patient has hyperkalemia with ECG changes (peaked T waves), which is a medical
emergency. The most immediate priority is to stabilize the cardiac membrane. Intravenous
calcium gluconate achieves this by antagonizing the effects of potassium on the myocardium.
While insulin with dextrose, sodium bicarbonate, and Kayexalate all help lower potassium, they
do not provide immediate cardioprotection. Therefore, calcium gluconate is the first and most
critical step.
Question 9: A 28-year-old female presents with a malar rash, arthritis, and proteinuria. A
renal biopsy reveals a "wire-loop" appearance on light microscopy. Which of the following is
the most likely diagnosis?
A. IgA Nephropathy
B. Membranous Nephropathy
Aligned With Current KDIGO Guidance and ABIM–ESENeph Nephrology Curriculum
Concepts, Covering Acute Kidney Injury and Acute Kidney Disease, Chronic Kidney
Disease Evaluation and Management, Glomerular Diseases, IgA Nephropathy, Lupus
Nephritis, ANCA-Associated Vasculitis, Diabetic Kidney Disease, Hypertension and
Kidney Disease, CKD-Mineral and Bone Disorder, Anemia of CKD, Electrolyte and Acid-
Base Disorders, Nephrotic and Nephritic Syndromes, Tubulointerstitial and Cystic
Kidney Diseases, Genetic Kidney Disorders, Kidney Replacement Therapy,
Hemodialysis and Peritoneal Dialysis, Kidney Transplantation, Nephrotoxic
Medications, Fluid and Volume Management, Renal Pharmacology, Pediatric and Adult
Nephrology, Critical Care Nephrology, Diagnostic Testing and Kidney Biopsy, Clinical
Decision-Making, Case-Based Questions, Practice Questions With Detailed Rationales,
and Comprehensive Board-Review Strategies
Question 1: A 68-year-old male with a history of hypertension and type 2 diabetes mellitus
presents with a serum creatinine of 2.8 mg/dL, up from 1.5 mg/dL six months ago. His
urinalysis shows 3+ proteinuria and no active sediment. A renal ultrasound reveals normal-
sized, echogenic kidneys. Which of the following is the most likely diagnosis?
A. Acute Interstitial Nephritis
B. Acute Tubular Necrosis
C. Diabetic Kidney Disease
D. Focal Segmental Glomerulosclerosis
CORRECT ANSWER: C. Diabetic Kidney Disease
Rationale: The patient's history of long-standing diabetes, progressive renal insufficiency, heavy
proteinuria, and normal-sized echogenic kidneys on ultrasound are classic features of diabetic
kidney disease (DKD). The lack of active sediment makes acute interstitial nephritis or acute
tubular necrosis less likely, as they are typically associated with pyuria or muddy brown casts,
respectively. While FSGS can present with nephrotic syndrome, the clinical context and gradual
rise in creatinine over six months strongly favor DKD.
Question 2: A 45-year-old female presents with acute-onset flank pain, nausea, and
microscopic hematuria. Her blood pressure is 155/95 mmHg. Urinalysis reveals dysmorphic
red blood cells and red blood cell casts. Which of the following is the most appropriate initial
diagnostic test to confirm the suspected diagnosis?
A. Computed Tomography Angiography (CTA)
B. Renal Biopsy
C. Urine Culture and Sensitivity
D. Serum Complement (C3, C4) Levels
,CORRECT ANSWER: A. Computed Tomography Angiography (CTA)
Rationale: The presentation of acute flank pain, hypertension, and hematuria with dysmorphic
RBCs and RBC casts is highly suggestive of a nephritic syndrome. While a renal biopsy is the gold
standard for glomerulonephritis, CTA is the most appropriate initial test to rule out renal artery
stenosis or thrombosis, which can present with similar symptoms, especially in a patient with
acute hypertension. CTA can also evaluate for other causes of acute flank pain. Serum
complement levels are useful for classifying glomerulonephritis but are not the initial diagnostic
step in this acute setting.
Question 3: A 72-year-old male with stage 4 chronic kidney disease (CKD) is started on
lisinopril for hypertension. One week later, his serum creatinine rises from 2.9 mg/dL to 3.7
mg/dL. Which of the following is the most appropriate next step in management?
A. Discontinue lisinopril immediately and start an ARB.
B. Increase the dose of lisinopril to achieve better blood pressure control.
C. Continue lisinopril and monitor renal function closely.
D. Obtain a renal ultrasound to assess for hydronephrosis.
CORRECT ANSWER: C. Continue lisinopril and monitor renal function closely.
Rationale: An acute rise in serum creatinine of up to 30% is an expected hemodynamic effect of
ACE inhibitors (like lisinopril) in patients with CKD, due to efferent arteriolar dilation. This rise is
usually benign and stabilizes within a few weeks. The medication should be continued as long
as the rise is not >30% from baseline and there are no signs of hyperkalemia or angioedema.
Discontinuing the drug would be premature, and increasing the dose is not indicated. A renal
ultrasound is unnecessary unless there is suspicion of obstruction, which is not suggested here.
Question 4: A 55-year-old male with a history of gout presents with severe pain in his right
great toe. His medications include allopurinol and hydrochlorothiazide. Laboratory studies
show a serum uric acid of 9.2 mg/dL and a creatinine of 1.3 mg/dL. Which of the following is
the most appropriate initial treatment for his acute gout flare?
A. Increase the dose of allopurinol.
B. Start colchicine.
C. Start probenecid.
D. Start febuxostat.
CORRECT ANSWER: B. Start colchicine.
Rationale: The patient is having an acute gout flare. Colchicine is a first-line agent for acute
flares, especially when initiated early. It is important not to start or increase urate-lowering
,therapy (like allopurinol) during an acute flare, as this can worsen the flare by causing a rapid
shift in uric acid levels. Probenecid is a uricosuric agent and is not used for acute flares.
Febuxostat is another urate-lowering agent and is not indicated for acute treatment. The
thiazide diuretic should be reviewed, but the immediate need is pain and inflammation control.
Question 5: A 68-year-old female with end-stage renal disease (ESRD) on hemodialysis
presents with a fever and chills. Her blood cultures are positive for Gram-positive cocci in
clusters. Which of the following is the most likely source of the infection?
A. Dialysis catheter
B. Urinary tract infection
C. Pneumonia
D. Infected arteriovenous fistula
CORRECT ANSWER: A. Dialysis catheter
Rationale: In patients on hemodialysis, the most common source of bacteremia, especially with
Gram-positive organisms like Staphylococcus aureus, is the vascular access device, particularly a
central venous catheter. While an infected AV fistula is possible, catheters have a significantly
higher infection rate. The other options are less common sources of bacteremia in this specific
patient population with a known vascular access device.
Question 6: A 50-year-old male with autosomal dominant polycystic kidney disease (ADPKD)
presents with sudden-onset, severe flank pain and gross hematuria. Which of the following is
the most likely cause of his symptoms?
A. Nephrolithiasis
B. Ruptured renal cyst
C. Renal infarction
D. Urinary tract infection
CORRECT ANSWER: B. Ruptured renal cyst
Rationale: Acute flank pain and gross hematuria in a patient with ADPKD are classic presenting
symptoms of a ruptured or hemorrhagic renal cyst. While nephrolithiasis and UTIs can occur,
cyst rupture is a well-known and common complication. Renal infarction is less common in
ADPKD. The suddenness and severity of the pain point toward a structural complication like a
cyst rupture.
, Question 7: A 60-year-old female with a history of recurrent UTIs is diagnosed with a left-
sided staghorn calculus. The stone is composed of struvite. Which of the following is the most
important component of the initial management strategy?
A. Extracorporeal shock wave lithotripsy (ESWL)
B. Complete stone removal via percutaneous nephrolithotomy (PCNL)
C. Antibiotic therapy based on urine culture and sensitivity
D. Dietary restriction of oxalate
CORRECT ANSWER: C. Antibiotic therapy based on urine culture and sensitivity
Rationale: Struvite (magnesium ammonium phosphate) stones are always associated with
urease-producing bacteria (most commonly Proteus). The most critical initial step is to identify
and treat the underlying infection with appropriate antibiotics. Complete stone removal with
PCNL is the definitive treatment for staghorn stones, but it should be done after a course of
antibiotics to reduce the risk of sepsis. ESWL is not effective for large staghorn calculi. Dietary
oxalate restriction is for calcium oxalate stones.
Question 8: A 42-year-old male with a history of hypertension is found to have a serum
potassium of 6.2 mEq/L. His ECG shows peaked T waves. Which of the following is the most
appropriate immediate treatment?
A. Oral sodium polystyrene sulfonate (Kayexalate)
B. Intravenous calcium gluconate
C. Intravenous insulin with dextrose
D. Intravenous sodium bicarbonate
CORRECT ANSWER: B. Intravenous calcium gluconate
Rationale: The patient has hyperkalemia with ECG changes (peaked T waves), which is a medical
emergency. The most immediate priority is to stabilize the cardiac membrane. Intravenous
calcium gluconate achieves this by antagonizing the effects of potassium on the myocardium.
While insulin with dextrose, sodium bicarbonate, and Kayexalate all help lower potassium, they
do not provide immediate cardioprotection. Therefore, calcium gluconate is the first and most
critical step.
Question 9: A 28-year-old female presents with a malar rash, arthritis, and proteinuria. A
renal biopsy reveals a "wire-loop" appearance on light microscopy. Which of the following is
the most likely diagnosis?
A. IgA Nephropathy
B. Membranous Nephropathy
