Bladder outflow obstruction is a common set of symptoms
It often presents with difficulty of micturition
The causes of bladder outflow obstruction are numerous. The common causes are:
- Benign prostatic hyperplasia
- Bladder neck hypertrophy
- Prostatic carcinoma
- Urethral strictures
History
The cardinal symptoms are:
- Hesitancy
- Poor stream
- Post micturition dribbling
In addition the stream may stop and start. Patients often void again after a short period. This is known as pis-en-deux. Straining to void will improve the flow in urethral stricture but is ineffectual in prostatic enlargement.
The irritative symptoms that accompany the cardinal symptoms are:
- Frequency
- Nocturia (rising at night)
- Urgency
- Incontinence
The patient may experience haematuria and dysuria (painful burning micturition).
Examination
Abdominal examination may reveal a palpable bladder which may or may not be tender. A digital rectal examination will assess the prostate. The prostate has two lobes separated by a central groove or sulcus. In prostate cancer the gland feels firm to hard. Nodules may be palpable in one or both lobes. The central sulcus may be obliterated and the surrounding tissues may be firmer or harder in more advanced cases. It may be soft and enlarged as in benign prostatic hyperplasia.
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Investigations
Blood Tests
- Full blood count (detects anaemia)
- Urea and creatinine (assesses renal function)
- PSA may detect prostatic carcinoma
Ultrasound
- These scans check for hydronephrosis in the kidney
Uroflowmetry
- The rate of voiding urine can be measured
Cystoscopy
- This is an endoscopic examination of the bladder. It will diagnose the cause of the obstruction. In this respect it is a qualitative test.
Urodynamic assessment
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This test involves catheterising the patient. The bladder is filled with fluid and then the patient passes the fluid. During the test the bladder and rectal pressures are monitored. From the information collected it is possible to quantify the degree of obstruction.
Ascending Urethrography
- This is an xray of the urethra with contrast medium inserted into the urethra. It is used to assess some strictures

Ascending Urethrogram showing multiple strictures
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