Renal and Urinary Disorders Practice Questions
20 free Renal and Urinary Disorders practice questions for the USMLE Step 1. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
A 9-year-old boy develops cola-colored urine 2 weeks after a streptococcal throat infection. Which finding is most characteristic of his condition?
- A Linear IgG deposition
- B Subepithelial humps
- C Mesangial IgA deposition
- D Subendothelial deposits
Correct answer: Subepithelial humps
Post-streptococcal glomerulonephritis is characterized by subepithelial immune complex 'humps.' It presents with hematuria and recent strep infection.
A patient presents with rapidly progressive renal failure and crescent formation on biopsy. Which antibody is most likely present?
- A Anti-dsDNA
- B Anti-GBM
- C Anti-centromere
- D p-ANCA
Correct answer: Anti-GBM
Anti-GBM antibodies cause Goodpasture syndrome, a form of RPGN with linear IgG deposition and crescent formation.
A 35-year-old woman presents with hematuria and hearing loss. Her father had a similar condition. Which mutation is most likely?
- A Type IV collagen gene defect
- B CFTR chloride channel mutation
- C β-globin chain gene mutation
- D p53 tumor suppressor mutation
Correct answer: Type IV collagen gene defect
Alport syndrome is caused by type IV collagen defects affecting basement membranes in kidney, ear, and eye.
A patient presents with hematuria and flank pain. CT shows a staghorn calculus. Which organism is most likely responsible?
- A E. coli
- B Proteus mirabilis
- C Staphylococcus saprophyticus
- D Candida albicans
Correct answer: Proteus mirabilis
Proteus produces urease, increasing urine pH and promoting struvite stone formation, causing staghorn calculi.
A patient with nephrotic syndrome has frothy urine and marked proteinuria. Which complication is most likely?
- A Hypokalemia
- B Hypercoagulability
- C Metabolic acidosis
- D Hyperphosphatemia
Correct answer: Hypercoagulability
Nephrotic syndrome causes loss of antithrombin III, increasing risk of thrombosis and hypercoagulability.
A man with BPH develops postrenal AKI. Which finding is most likely in early obstruction?
- A Decreased GFR and decreased RBF
- B Decreased GFR and increased RBF
- C Increased GFR and increased RBF
- D Increased GFR and decreased RBF
Correct answer: Decreased GFR and increased RBF
Early obstruction increases tubular pressure, decreasing GFR but increasing renal blood flow due to vasodilation.
A patient presents with oliguria and muddy brown casts. Which diagnosis is most likely?
- A Acute interstitial nephritis
- B Acute tubular necrosis
- C Membranous nephropathy
- D Minimal change disease
Correct answer: Acute tubular necrosis
Muddy brown casts are characteristic of acute tubular necrosis, typically due to ischemia or nephrotoxins.
A patient with lupus develops proteinuria and hematuria. Biopsy shows 'wire-loop' lesions. Which condition is this?
- A Minimal change disease
- B Membranoproliferative GN
- C Lupus nephritis
- D IgA nephropathy
Correct answer: Lupus nephritis
Wire-loop lesions indicate immune complex deposition in lupus nephritis, especially in diffuse proliferative glomerulonephritis.
A young man develops hematuria 2 days after a viral upper respiratory infection. What is the likely diagnosis?
- A IgA nephropathy
- B Post-streptococcal GN
- C Membranous GN
- D FSGS
Correct answer: IgA nephropathy
IgA nephropathy causes episodic hematuria following mucosal infections. It is the most common glomerulonephritis worldwide.
A diabetic patient has albuminuria. Which drug slows progression of his kidney disease?
- A Loop diuretics
- B ACE inhibitors
- C Beta-blockers
- D Calcium channel blockers
Correct answer: ACE inhibitors
ACE inhibitors decrease intraglomerular pressure and reduce proteinuria, slowing diabetic nephropathy progression.
A biopsy shows 'spike and dome' appearance with subepithelial deposits. Which condition is this?
- A Membranous nephropathy
- B Minimal change disease
- C Membranoproliferative GN
- D FSGS
Correct answer: Membranous nephropathy
Membranous nephropathy shows subepithelial immune complex deposits forming spikes on silver stain.
A child with periorbital edema has a biopsy showing podocyte effacement on electron microscopy. Which condition is this?
- A FSGS
- B Minimal change disease
- C Diabetic nephropathy
- D Alport syndrome
Correct answer: Minimal change disease
Minimal change disease presents with selective albuminuria and podocyte foot process effacement. It responds well to steroids.
A patient develops AKI after receiving IV contrast. Which biochemical change is expected?
- A Increased BUN/creatinine ratio
- B Increased fractional excretion of sodium
- C Increased creatinine
- D Increased urine osmolality
Correct answer: Increased creatinine
Contrast-induced nephropathy is an intrinsic AKI marked by a rising serum creatinine; intense renal vasoconstriction typically produces a low FeNa (<1%) and a normal BUN/creatinine ratio.
A patient with chronic lithium use presents with polyuria and hypernatremia. Which renal condition is most likely?
- A Central diabetes insipidus
- B Nephrogenic diabetes insipidus
- C SIADH
- D Adrenal crisis
Correct answer: Nephrogenic diabetes insipidus
Lithium damages collecting ducts, causing nephrogenic diabetes insipidus with inability to concentrate urine.
A patient with hepatitis C develops nephrotic syndrome. Which renal disease is associated with this infection?
- A Minimal change disease
- B Membranous nephropathy
- C FSGS
- D MPGN type I
Correct answer: MPGN type I
Hepatitis C is strongly associated with type I membranoproliferative glomerulonephritis due to immune complex deposition.
A biopsy shows 'tram-track' appearance of the basement membrane. Which condition is this?
- A Minimal change disease
- B Membranous nephropathy
- C Membranoproliferative GN
- D IgA nephropathy
Correct answer: Membranoproliferative GN
MPGN shows splitting of the basement membrane, giving a tram-track appearance on microscopy.
A patient with ATN is in the oliguric phase. Which electrolyte abnormality is expected?
- A Hypokalemia
- B Hyperkalemia
- C Hypernatremia
- D Hypophosphatemia
Correct answer: Hyperkalemia
During the oliguric phase, impaired excretion leads to hyperkalemia, metabolic acidosis, and fluid overload.
A 25-year-old man with hematuria and anemia has sickle cell disease. Which renal condition is most likely?
- A Renal papillary necrosis
- B Minimal change disease
- C Membranous nephropathy
- D RPGN
Correct answer: Renal papillary necrosis
Sickle cell disease causes ischemia of renal papillae leading to papillary necrosis, presenting with hematuria and flank pain.
A patient has nephritic syndrome with low complement levels and 'starry sky' immunofluorescence. Which condition is this?
- A Post-streptococcal GN
- B IgA nephropathy
- C FSGS
- D Membranous nephropathy
Correct answer: Post-streptococcal GN
PSGN shows granular deposits ('starry sky') and low complement due to immune complex deposition.
A man on aminoglycosides develops AKI. What is the mechanism?
- A Acute interstitial nephritis
- B Pre-renal azotemia
- C Acute tubular necrosis
- D Post-renal obstruction
Correct answer: Acute tubular necrosis
Aminoglycosides cause nephrotoxicity by damaging proximal tubular cells, leading to acute tubular necrosis.