Urinary Tract Calculi Flashcards
What are urinary tract calculi? (2 things)
- Stones formed anywhere in UT
- Caused by precipitations of solutes in urine
What are some general risk factors for urinary tract calculi? (3 things)
- Male
- FHx
- Dehydration (increases concentration of urine solutes)
What medical conditions increase the risk of urinary tract calculi? (5 things)
- UTI
- Gout (high uric acid)
- Hyperparathyroidism (high Ca)
4 HTN - DM
What features of a diet increase the risk of urinary tract calculi? (3 things)
- High Na = reduces Na + Ca reabs @ PCT = hypercalciuria
- High Ca
- High oxalate
What medications increase the risk of urinary tract calculi?
Loop diuretics = X Ca reabs @ DCT
What foods increase oxalate? (5 things)
- Chocolate
- Tea
- Rhubarbs
- Strawberries
- Nuts
What causes Calcium oxalate stones?
Metabolic / idiopathic
What causes Calcium phosphate stones?
Metabolic / idiopathic
What causes Magnesium Ammonium Phosphate stones?
UTI
What causes Urate stones?
Hyperuricaemia
What causes Cystine phosphate stones?
Renal tubular defects
What are the most common sites for stones to lodge? (3 things)
- Pelviureteric junction (renal pelvis + ureter)
- Pelvic brim (ureteral crossing of iliac vessels)
- Vesicoureteric junction (urinary bladder + ureter)

When can urinary tract calculi be asymptomatic? (2 things)
- Small stones
- Stones @ renal pelvis / bladder
What are the clinical features of urinary tract calculi? (6 things)
- Fever (inf / pyelonephritis)
- N+V
- Abd pain (colicky, unilateral) (bc ureteric obst)
- Costophrenic Angle Tenderness
- Haematuria
- Inability to lie still (differentiates from peritonitis)
What is Costovertebral Angle tenderness?

Where does the Abd pain in Urinary Tract Calculi radiate to? (2 things)
- Groin
- Testes / labia majora
What are other differentials that present similarly to urinary tract calculi? (4 things)
- Acute appendicitis
- Biliary colic
- Diverticulitis
- Testicular torsion
How do you differentiate Acute Appendicitis from Urinary Tract Calculi?
UTC = causes FLANK pain
How do you differentiate Biliary Colic from Urinary Tract Calculi?
UTC pain NOT related to eating
How do you differentiate Diverticulitis from Urinary Tract Calculi?
UTC NO bloody stools
How do you differentiate Testicular Torsion from Urinary Tract Calculi?
UTC = causes FLANK pain
What lab tests should be done for Urinary Tract Calculi? (5 things)
- Urine dip (haematuria / infection)
- FBC (raised WCC in infection)
- CRP (raised in infection)
- U&Es
- renal function
- urate + calcium levels (to find stone type)
- stone in urine –> retrieve + analyse to find type - Urine culture (if infection present)
What is the Gold standard imaging for Urinary Tract Calculi?
Non-contrast CT of KUB (kidneys ureters and bladder)
Why is non-contrast CT of KUB the Gold standard imaging for UTC? (2 things)
- 99% stones visible
- Excludes acute abdomen differentials (e.g ruptured AAA)