bladder outflow obstruction

Last reviewed 07/2021

Bladder outflow obstruction occurs where there is some impediment to the normal smooth, complete and rapid voiding of the bladder - the term 'bladder outflow obstruction' is encompassed within the term 'lower urinary tract symptoms'

Lower urinary tract symptoms (LUTS) comprise storage, voiding and post-micturition symptoms affecting the lower urinary tract

  • there are many possible causes of LUTS such as abnormalities or abnormal function of the prostate, urethra, bladder or sphincters
    • in men, the most common cause is benign prostate enlargement (BPE), which obstructs the bladder outlet. BPE happens when the number of cells in the prostate increases, a condition called benign prostatic hyperplasia
      • other conditions that can cause LUTS include detrusor muscle weakness or overactivity, prostate inflammation (prostatitis), urinary tract infection, prostate cancer and neurological disease

    • LUTS in men are best categorised into voiding, storage or post-micturition symptoms to help define the source of the problem

      • voiding symptoms include weak or intermittent urinary stream, straining, hesitancy, terminal dribbling and incomplete emptying
      • storage symptoms include urgency, frequency, urgency incontinence and nocturia

    • the major post-micturition symptom is post-micturition dribbling, which is common and bothersome

    • age is an important risk factor for LUTS and the prevalence of LUTS increases as men get older. Bothersome LUTS can occur in up to 30% of men older than 65 years
  • refer men for specialist assessment if they have LUTS complicated by recurrent or persistent urinary tract infection, retention, renal impairment that is suspected to be caused by lower urinary tract dysfunction, or suspected urological cancer