Editing Non-gonococcal urethritis (section)

==Diagnosis==
It has been easy to test for the presence of gonorrhea by viewing a [[Gram stain]] of the urethral discharge under a microscope: The causative organism is distinctive in appearance; however, this works only with men because other non-pathogenic [[gram-negative]] microbes are present as [[Bacteria in the human body|normal flora]] of the vagina in women.  Thus, one of the major causes of urethritis can be identified (in men) by a simple common test, and the distinction between gonococcal and non-gonococcal urethritis arose for this reason.

Non-gonococcal urethritis (NGU) is diagnosed if a person with urethritis has no signs of gonorrhea bacteria on laboratory tests. 

In men, the most frequent cause of NGU (15%-55% of cases) is ''[[Chlamydia trachomatis]]''.<ref name=Ferri2024>{{cite book |last1=Ferri |first1=Fred F. |title=Ferri's Clinical Advisor 2024 |date=2023 |publisher=Elsevier |location=Philadelphia |isbn=978-0-323-75576-4 |pages=356 |chapter-url=https://books.google.com/books?id=hs3FEAAAQBAJ&pg=PA356|language=en |chapter=Chlamydia genital infections}}</ref>

===Idiopathic urethritis or non-specific urethritis===
Historically, the terms '''idiopathic urethritis''' (US English)<ref name=":0">{{Cite journal |last1=Wetmore |first1=Catherine M. |last2=Manhart |first2=Lisa E. |last3=Golden |first3=Matthew R. |date=November 2009 |title=Idiopathic urethritis in young men in the United States: prevalence and comparison to infections with known sexually transmitted pathogens |journal=The Journal of Adolescent Health |volume=45 |issue=5 |pages=463–472 |doi=10.1016/j.jadohealth.2009.06.024 |issn=1054-139X |pmc=2764555 |pmid=19837352}}</ref> or '''non-specific urethritis''' (British English)<ref>[http://www.gum.nhs.uk/leaflets/nsu.asp Non-specific Urethritis (NSU)] {{Webarchive|url=https://web.archive.org/web/20120317183837/http://www.gum.nhs.uk/leaflets/nsu.asp|date=2012-03-17}}, NHS, Genito-Urinary Medicine (GUM)</ref> have been used as synonyms for nongonococcal urethritis. "[[Idiopathic disease|Idiopathic]]" and "[[wikt:nonspecific|non-specific]]" are medical term meaning "specific cause has not been identified", and in this case refers to the detection of urethritis, and the testing for but found negative of gonorrhea. In this sense, the most likely cause of NSU is a [[chlamydia infection]].

However, the term NSU is sometimes distinguished and used to mean that both gonorrhea and chlamydia have been ruled out.<ref>{{Cite web |url=http://www.fpwa.org.au/healthinformation/informationsheets/nsu/ |title=Non-specific urethritis (NSU) and Cervicitis |access-date=2009-05-15 |archive-date=2017-12-15 |archive-url=https://web.archive.org/web/20171215163650/http://www.fpwa.org.au/healthinformation/informationsheets/nsu/ |url-status=dead }}</ref> Thus, depending on the sense, chlamydia can either be the most likely cause or have been ruled out, and frequently detected organisms are ''[[Ureaplasma urealyticum]]'' and ''[[Mycoplasma hominis]]''.

However, in 20-50% of cases, a specific cause for urethritis can't be identified, in which case a diagnosis of idiopathic urethritis is a [[diagnosis of exclusion]].<ref name=":0" />