Hydronephrosis is swelling of the kidney's collecting system because urine cannot drain normally. It points to a blockage or reflux from stones, an enlarged prostate, tumors or pregnancy, and a lasting blockage can permanently damage the kidney.
Key symptoms
- Flank pain that may spread to the groin
- Nausea and vomiting
- Less urine or trouble passing urine
- Fever and chills when infection is present
- Sometimes no symptoms when the blockage develops slowly
What you find on exam
- Costovertebral angle tenderness
- Palpable distended bladder
- Enlarged prostate on rectal exam
- Fever, low blood pressure or other signs of sepsis
Tests
- Renal ultrasound: dilated renal pelvis and calyces, graded mild to severe
- Bladder scan for post-void residual
- Urinalysis, urine culture, creatinine and electrolytes
- Non-contrast CT to find stones or other causes
Treatment basics
- Relieve lower tract blockage with a urinary catheter
- Ureteral stent or nephrostomy tube for upper tract blockage
- Infected obstruction: urgent drainage plus IV antibiotics
- Treat the cause: stone removal, prostate therapy or tumor workup
- Watch for heavy urine output after the blockage is relieved
Red flags
- Fever with an obstructed kidney (urologic emergency)
- Rising creatinine or no urine output
- Blockage of a solitary kidney or of both kidneys
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.