Back-to-Basics: Urinary Retention

EM Daily - Acute Urinary Retention 

Lynn Manganiello 



  • Dont mistake overflow incontinence as spontaneous voiding 

  • Consider other causes aside from BPH (although this is the most common cause) 

  • Must perform pelvic exam in female patients with urinary retention 


Pathophysiology of urine storage: 

  • Beta-adrenergic/anticholinergic - urine storage, relaxation of detrusor  

  • Alpha adrenergic - contraction of bladder neck and internal sphincter 

Pathophysiology of urination: 

  • Cholinergic - contraction of bladder detrusor 

  • Alpha-adrenergic inhibition - internal sphincter of bladder neck and urethras sphincter relaxation 


Differential diagnosis: 

Male-specific = BPH or prostate cancer, phimosis, paraphimosis, meatal stenosis, prostatitis 

Female-specific = obstruction from pelvic organ prolapse, ovarian or uterine tumor; incontinence surgery, PID 


Considerations for both males and females: 

  • Obstruction - stricture, bladder calculi or neoplasm, foreign body 

  • Neurogenic - Neuromusuclar disease, spinal cord compression, nerve injury from pelvic surgery 

  • Traumatic injury of urethra or bladder 

  • Extra-urinary - peri-rectal or pelvic abscess, rectal or retroperitoneal mass, fecal impaction, AAA, rectal prolapse 

  • Psychogenic - stress, anxiety 

  • Infectious - cystitis, HSV, zoster in pelvic region, local abscess 

  • Pharmacologic - anticholinergic, sympathomimetic agents, opioids, benzodiazepines, psychoactive agents, beta agonists, CCBs, decongestants, muscle relaxants, NSAIDs 


With the above differential in mind, be sure to ask: 

  • PMH and PSH 

  • Medication list  

  • Recent events or trauma 

  • Associated symptoms 


Physical Exam: 

  • GU/perineal exam 

  • Pelvic exam in female patients to detect possible pelvic or adnexal mass, pelvic organ prolapse 



-   Post-void residual is diagnostic 

  • UA - rule out infection 

  • Chemistry - renal function, electrolytes 



-Treat underlying cause 

-Often requires placement of foley catheter 

-Follow up with urology in 3-7 days if appropriate for outpatient management 

-Add flomax if BPH is suspected cause 

-Admit if clot retention, sepsis, neurologic cause 

-Watch for excessive diuresis (>200cc/h of urine output over 2 hours) 


Special considerations: 

  • If recent urologic procedure > consult urology 

  • Clot retention > may need triple lumen foley (3-way” foley) for irrigation with saline until clear 

  • Post-op > typically only need straight cath without leaving foley in place, then voiding trial 




  1. Billet, Michael, and Thomas Andrew Windsor. Urinary Retention.” Emergency Medicine Clinics of North America, vol. 37, no. 4, 2019, pp. 649660., doi:10.1016/j.emc.2019.07.005.  
  2. Yen, David Hung-Tsang and Chen-Hsen LeeAcute Urinary Retention. Tintinallis Emergency Medicine: A Comprehensive Study Guide, 8th Ed. Judith E. Tintinalli, et al. New York,  NY: McGraw-Hill, 2016.