I. Isolated hematuria (without protein, cells, casts)
- Usually due to bleeding in urinary tract
- If blood is present evenly throughout voiding ("total hematuria") suggests source is bladder or above, because blood has had opportunity to mix with urine; otherwise, probably of urethral or prostatic origin
- Causes
- Calculi
- Neoplasm
- TB
- Trauma
- Prostatitis
- Primary renal causes (rare): focal glomerulonephritis (usually has RBC casts), analgesic nephropathy, sickle cell anemia (usually sl. proteinuria, papillary necrosis, and azotemia)
- Approach:
- Px of prostate and external urethra
- Platelets/coags
- Urine cx
- IVP and renal u/s
- If no lesion seen, cystoscopy and maybe retrograde pyelography
- If blood from only one ureter, suggests local process rather than primary renal disease
- Further imaging: CT kidney, renal arteriography
- Urine cytology
II. Hematuria with UTI-a frequent occurrence; should at least repeat u/a after tx to make sure it's resolved
III. Hematuria with evidence of renal disease
- RBC casts are formed by combination of tubular blood & tubular mucoprotein
- Caused by primary renal disease, e.g. glomerulonephritis, tubulointerstitial disease, nephronal vasculitis
- Often accompanied by proteinuria (glomerular or tubular)
- Still need w/u for sources of urinary tract bleeding
Crenated red cells traditionally thought to indicate glomerular source, but are highly nonspecific Acanthocytes (donut-shaped RBCs with central hole) are specific for upper-tract source