Associated symptoms help determine the cause. Associated renal angle pain suggests a renal or ureteric source for the haematuria, whereas suprapubic pain suggests a bladder source. Painless frank haematuria is not infrequently due to bladder cancer.
As stated above, while patients sometimes present acutely to their family doctors or to hospital emergency departments with haematuria, it is seldom a urological emergency, unless the bleeding is so heavy that the patient has become anaemic as a consequence (this is rare), or the bladder or a ureter has become blocked by clots (in which case the patient presents with retention of urine or with ureteric colic, which may mimic that due
4 H. HASHIM AND J.REYNARD
to a stone). We investigate all patients with haematuria, and recommend, as a bare minimum, urine culture and cytology, renal ultrasonography, and flexible cystoscopy, with more complex investigations such as an IVU or computed tomography (CT) scan in selected groups.
OLIGURIA, ANURIA,AND INABILITY TO PASS URINE
Anuria is defined as complete absence of urine production and usually indicates obstruction to the urinary tract. The level of obstruction may be at the outlet of the bladder, or at the level of the ureters bilaterally. Unrelieved bilateral urinary tract obstruction leads rapidly to acute renal failure, which may have very serious consequences (e.g., hyperkalaemia, fluid overload).
If the level of obstruction is at the outlet of the bladder, abdominal examination will reveal a percussable and palpably distended bladder. Urine will be present in the bladder on catheterisation, and urine output will resume once a catheter has bypassed the obstruction. The commonest cause is benign pro-static enlargement and less commonly malignant enlargement of the prostate.
If the obstruction is at the level of the lower ureters or ureteric orifices, the bladder will not be palpable or percussable. Catheterisation will reveal no or a very low volume of urine in the bladder and there will be no improvement in urine output, or of renal function post-catheterisation. Causes include locally advanced prostate cancer, extensive involvement of the trigone of the bladder by bladder cancer, and locally advanced cervical or rectal cancer. Rectal or vaginal examination may reveal a cervical, prostatic, or rectal cancer and cystoscopic examination of the bladder may demonstrate a bladder cancer.