Loin Pain/Hematuria Syndrome



  • A rare and poorly understood syndrome characterized by unexplained chronic, severe, intermittent or persistent, unilateral or bilateral loin/flank pain with microscopic or gross hematuria
  • It is a diagnosis of exclusion.
  • Treatment focuses on pain management which requires reassurance, careful management of analgesia, and psychological support.




  • 0.01%
  • Range: 10 to 70 years
  • 70% of cases are in females.
  • More common in white female in 20s to 30s

Etiology and Pathophysiology

  • Uncertain
  • Several hypotheses have been proposed such as microvascular abnormalities, complement activation on arterioles, renal vasospasm, veno-caliceal fistula, abnormal ureteral peristalsis, intratubular crystal formation, abnormal platelet function, or psychogenic nature.
  • Glomerular basement membrane abnormalities (too thick or thin) leading to glomerular wall rupture and passage of red blood cell (RBC) into the urinary space, causing tubular obstruction and back leak of glomerular filtrate with resultant parenchymal edema and stretching of renal capsule have been proposed.

No report of genetic involvement

Risk Factors


General Prevention


Commonly Associated Conditions

  • Somatoform disorder
  • 50% of patients have a history of nephrolithiasis.

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