Blood clots indicate a glomerular source.
+Red cell casts indicate a hematologic source.
+Smoke-colored urine usually has a renal source.
+Proteinuria indicates a postrenal source.
+Hematuria present throughout urination indicates a nonglomerular renal source.
The amount of blood in the urine does not correlate with the severity of the condition that caused it. In fact, as little as 1 mL of blood in 1 L of urine can cause grossly appreciable hematuria. The causes of hematuria can be roughly divided into the following four groupings: (1) Hematologic (sickle cell disease, coagulopathies); (2) intrarenal–glomerular (systemic lupus, Wegener granulomatosis, Goodpasture syndrome); (3) intrarenal–nonglomerular (polycystic kidney disease, acute interstitial nephritis, trauma); and (4) postrenal (renal stone, cystitis, tumor, etc.) causes. Blood clots indicate a nonglomerular renal or postrenal source. Red cell casts and proteinuria indicate a renal source. Hematuria that is present throughout voiding is usually due to a bladder, ureter, or renal source.