Editing Urine test (section)

==Specimen collection==
[[File:Trace metal-free 24 hour urine container.jpg|thumb|Example of a container used for collecting 24-hour urine samples. This particular container is free of [[trace metal]]s to allow for accurate measurement of these substances in urine.]]
The techniques used to collect urine specimens vary based on the desired test. A random urine, meaning a specimen that is collected at any time, can be used for many tests. However, a sample collected during the first urination of the morning (first morning specimen) is preferred for tests like urinalysis and pregnancy screening because it is typically more concentrated, making the test more [[Sensitivity and specificity|sensitive]].{{sfn|Brunzel|2018|pp=19–22}}{{sfn|Mundt|Shanahan|2016|p=264}} Because the concentration of many substances in the urine varies throughout the day, some tests require timed urine collections, in which the patient collects all of their urine into a container for a given period of time (commonly 24 hours). A small amount of the specimen is then removed for testing. Timed collections are commonly used to measure [[Urine creatinine|creatinine]], [[urea]], [[urine protein]],  [[hormones]] and [[electrolytes]].{{sfn|Brunzel|2018|pp=19–22}}{{sfn|Mundt|Shanahan|2016|pp=75–6}} 

If urine is needed for [[microbiological culture]], it is important that the sample is not contaminated. In this case, the proper collection procedure involves cleaning the genital area, beginning to urinate into the toilet, and then filling the specimen container before completing the urination into the toilet. This is called a "midstream clean catch" collection.{{sfn|Brunzel|2018|pp=19–22}} Research has shown many women are unsure of how to take a midstream sample or why it is needed.<ref>{{cite journal |date=11 December 2022 |title=Do women know how to take a urine sample? |url=https://evidence.nihr.ac.uk/alert/do-women-know-how-to-take-a-urine-sample/ |journal=NIHR Evidence}}</ref><ref>{{cite journal | vauthors = Glogowska M, Croxson C, Hayward G | title = Women's information needs around urine testing for urinary tract infections: a qualitative study | journal = The British Journal of General Practice | volume = 72 | issue = 717 | pages = e244–e251 | date = April 2022 | pmid = 35190371 | pmc = 8869185 | doi = 10.3399/BJGP.2021.0564 }}</ref>

If the subject is not able to urinate voluntarily, samples can be obtained using a [[urinary catheter]] or by inserting a needle through the abdomen and into the bladder ([[suprapubic aspiration]]).<ref name="statpearls">{{cite journal| vauthors = Queremel Milani DA, Jialal I |title=Urinalysis|date=8 May 2022|journal=StatPearls|pmid=32491617 |url=https://www.ncbi.nlm.nih.gov/books/NBK557685/|access-date=13 July 2022|archive-date=5 April 2022|archive-url= https://web.archive.org/web/20220405015846/https://www.ncbi.nlm.nih.gov/books/NBK557685/|url-status=live}}</ref> In infants and young children, urine can be collected into a bag attached to the genital region, but this is associated with a high risk of contamination.{{sfn|Brunzel|2018|pp=19–22}}