Skip to Main Content


Acute urinary retention is a common painful urologic emergency characterized by a sudden inability to pass urine, and is associated with lower abdominal distention or pain. Most patients with urinary retention are elderly men, and the incidence and risk increase with age. The most common cause of urinary retention is benign prostatic hyperplasia (BPH), with or without precipitating factors, inducing urinary bladder outlet obstruction.1 A comprehensive history and physical examination are needed to identify the underlying disease process and the factors triggering obstruction. The current management of urinary retention involves the placement of a catheter (urethral or suprapubic), supportive medical therapy, and disposition decision making.


The reported incidence of acute urinary retention in large population-based studies varies from 2.2 to 6.8 per 1000 men per year2–5 with a 4% to 73% 10-year cumulative risk.6,7 It is estimated that 1 in 10 men in their 70s will experience urinary retention within the next 5 years. The risk for men in their 80s is nearly 1 in 3.2 The risk factors for urinary retention in men are related to age, symptom severity, prostate volume (size), and urinary flow rate.2 There is a 20% recurrence rate within 6 months after an episode of urinary retention.5 The recently available data on the incidence of urinary retention based on different descriptive studies, including population-based, observational, and placebo-control group of BPH studies, varied from 1.9% to 39.0% overall, 0.37% to 13.0% per year, and 3.7 to 130.0 per 1000 patient-years.8 This risk is cumulative and increases with advancing age. Due to a very low occurrence rate in females, few scientific data documenting the incidence of urinary retention in woman are available.


In certain patient groups, the onset of urinary retention predicts significant future mortality.9 In men with spontaneous urinary retention, the mortality rate at 1 year increases from 4.1% in patients aged 45 to 54 years to 32.8% in those aged 85 years and older. Men with spontaneous urinary retention and comorbidity who are admitted to hospital have a higher mortality at both 90 days and at 1 year than those without comorbidity in the corresponding age groups. Approximately half of the men aged 85 years and older with at least one comorbid condition died within the first year after acute urinary retention.9


Urinary retention results from increased resistance to urine flow by mechanical or dynamic means, diminished neurogenic control of detrusor muscle contractility, and subsequent decompensation of voiding function. The voiding process, or micturition, involves the complex integration and coordination of high cortical neurologic (sympathetic, parasympathetic, and somatic) and muscular (detrusor and sphincter smooth muscle) functions. Normal bladder voiding requires coordinated contraction of the bladder smooth musculature, concomitant lowering of resistance at the level of the smooth and striated sphincter muscle, and absence of anatomic obstruction. Therefore, neurologic modulation plays a major role in the voiding process.


Sympathetic innervation, responsible for ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessMedicine Full Site: One-Year Subscription

Connect to the full suite of AccessMedicine content and resources including more than 250 examination and procedural videos, patient safety modules, an extensive drug database, Q&A, Case Files, and more.

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessMedicine

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.