Editing Urinary retention (section)

== Diagnosis ==
[[File:Urinaryobstruction.png|thumb|As seen on axial CT]]
[[File:Ultrasound of trabeculated urinary bladder.jpg|thumb|[[Medical ultrasonography|Ultrasonography]] showing a trabeculated wall, seen as small irregularities mainly at left (superior part). This is strongly associated with urinary retention.<ref>{{cite book|title=Glenn's Urologic Surgery|url=https://books.google.com/books?id=GahMzaKgMKAC&pg=PA306 |page=306 | vauthors = Graham SE, Keane TE, Glenn JF |publisher=Lippincott Williams & Wilkins|year=2010|isbn=978-0-7817-9141-0}}</ref>]]
Analysis of urine flow may aid in establishing the type of [[micturition]] (urination) abnormality. Common findings, determined by ultrasound of the bladder, include a slow rate of flow, intermittent flow, and a large amount of urine retained in the bladder after urination. A normal test result should be 20–25&nbsp;[[Milliliter|ml]]/s peak flow rate. A post-void residual urine greater than 50&nbsp;ml is a significant amount of urine and increases the potential for recurring urinary tract infections.{{cn|date=July 2022}} In adults older than 60 years, 50-100&nbsp;ml of residual urine may remain after each voiding because of the decreased contractility of the [[Detrusor urinae muscle|detrusor muscle]].<ref name="Stof2017" /> In chronic retention, ultrasound of the bladder may show massive increase in bladder capacity (normal capacity is 400-600&nbsp;ml).{{cn|date=April 2021}}

Non-neurogenic chronic urinary retention does not have a standardized definition; however, urine volumes >300mL can be used as an informal indicator.<ref name=Stof2017>{{cite journal | vauthors = Stoffel JT | title = Non-neurogenic Chronic Urinary Retention: What Are We Treating? | journal = Current Urology Reports | volume = 18 | issue = 9 | pages = 74 | date = September 2017 | pmid = 28730405 | doi = 10.1007/s11934-017-0719-2 | s2cid = 12989132 }}</ref> Diagnosis of urinary retention is conducted over a period of 6 months, with 2 separate measurements of urine volume 6 months apart. Measurements should have a PVR (post-void residual) volume of >300ml.<ref name=Stof2017/>

Determining the serum [[prostate-specific antigen]] (PSA) may help diagnose or rule out prostate cancer, though this is also raised in BPH and [[prostatitis]]. A [[TRUS]] biopsy of the prostate (transrectal ultrasound guided) can distinguish between these prostate conditions. Serum [[urea]] and [[creatinine]] determinations may be necessary to rule out backflow kidney damage. [[Cystoscopy]] may be needed to explore the urinary passage and rule out blockages.{{cn|date=April 2021}}

In acute cases of urinary retention where associated symptoms in the lumbar spine are present such as pain, numbness ([[saddle anesthesia]]), parasthesias, decreased anal sphincter tone, or altered deep tendon reflexes, an MRI of the lumbar spine should be considered to further assess [[cauda equina syndrome]].{{cn|date=April 2021}}