Hematuria, especially in the outpatient setting, can arise from a variety of causes, ranging from over-exertion to bladder cancer. The first step in the evaluation is to consider the anatomical source, based on symptoms, casts, and RBC morphology. See below for the various causes of hematuria and clues to the etiology:
Glomerular: Acute GN can present as sudden onset of hematuria, proteinuria, RBC casts. RBC casts are pathognomonic for glomerular disease. Absence of these findings does not r/o glomerular disease. Look at the urine, as dysmorphic RBCs point to the glomerulus. Blood clots are a clue that this is NOT glomerular, as the urokinase and TPA activators in the glomeruli and tubules prevent clot formation.
Renal (non-glomerular): 90% of tumors are renal cell. Only 4% of renal cell cancer cases occur before age 40. Early detection may greatly improve survival. PCKD and hereditary nephritis can also cause hematuria.
Postrenal: Consider stones, infection, cancers. Excellent prognosis for TCC if detected early, although 22% of cases of transitional cell cancer are not associated with hematuria.
Hematologic: Therapeutic anticoagulation or antiplatelet therapy does not cause hematuria. Must r/o underlying disease. Pts with sickle cell trait or disease are at risk for papillary necrosis causing hematuria.
Other: Exercise or trauma (the Foley!) induced hematuria, endometriosis of urinary tract, “loin pain hematuria”.