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Urinary Tract Stones (Urolithiasis)

​​​​Urinary tract stones, ureteric stones, bladder stones, kidney stones, haematuria (blood in the urine), CT urogram, ureteroscopy, extracorporeal shockwave lithotripsy (ESWL), laser lithotripsy. 


​Renal and ureteric stones are common conditions involving more than 10% of the local population. Singapore is located along the global ‘stone belt’ where the climate and social factors are conducive for urinary stone formation.

80% of stones are composed of calcium oxalate or phosphate. Stones that block the urinary system can result in permanent damage of the kidney if not treated.


Signs and Symptoms

​Sudden to gradual onset of colicky flank pain radiating to the abdomen, haematuria (macroscopic or microscopic), nausea, vomiting or fever. If the stones occur in the bladder, there can be pain in the pelvis and during urination. ​​


Causes and Risks

Common risk factors include: ​
  • Poor oral fluid intake
  • High oxalate intake (beans, beer, berriers, coffee, spinach, potatoes)
  • High animal-derived protein intake

Other risk factors include:
  • Family history of kidney stones
  • Medical conditions such as chronic kidney disease
  • Gastric bypass procedures
  • Low calcium intake

Treatments and Programmes

Oral hydration is recommended to prevent concentrated urine that can predispose to stone formation (recommended daily fluid intake of at least 2L). The gold standard imaging for urinary tract stones is non-contrast CT scan (CT KUB). ​

Depending on the location of the stone (eg., kidney, ureter, bladder), various techniques will be used to remove the stones, including ESWL, ureteroscopy and laser lithotripsy, percutaneous nephrolithotripsy (PCNL) and cystoscopy. ​

​ If there is infection of the urinary tract due to stones, antibiotics should be initiated. Adequate pain relieved should also be given at presentation.


​     Contributed​ by Department of Surgery​.