Editing Excretory system (section)

=== Kidney stones ===
{{Main|Kidney stone disease}}

Scientifically, masses referred to as a renal calculus or nephrolith, or more commonly, "kidney stones", are solid masses of crystals that may be a variety of shapes, sizes, and textures, that can reside within one or both of the kidneys.<ref name=":1">{{Cite web | url=https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones/definition-facts | title=Definition & Facts for Kidney Stones &#124; NIDDK}}</ref> Kidney stones form when the balance is off between the concentration of substances that pass through urine, and the substances that are supposed to dissolve them. When substances are not properly dissolved, they have the ability to build up, and form these kidney stones. These stones are most commonly made up of substances such as calcium, cystine, oxalate, and uric acid, as these are the substances that normally would dissolve within the urine. When they do not dissolve correctly and further build up, they will commonly lodge themselves in the urinary tract and in this case, are usually small enough to pass through urine. In extreme situations, however, these stones may lodge themselves within the tube that connects the kidney and the bladder, called the ureter. In this case, they become very large in size and will most likely cause great pain, bleeding, and possibly even block the flow of urine.<ref>{{Cite journal|doi=10.1001/jama.2012.6217|pmid=22797461|title=Kidney Stones|journal=JAMA|volume=307|issue=23|pages=2557|year=2012|last1=Punnoose|first1=Ann R.|last2=Golub|first2=Robert M.|last3=Lynm|first3=Cassio|doi-access=free}}</ref> These can occur in both men and women, and studies show that around 12% of men, and 8% of women in America will develop kidney stones within their lifetime.<ref>{{cite journal |last1=Coe |first1=F. L. |title=Kidney stone disease |journal=Journal of Clinical Investigation |date=October 2005 |volume=115 |issue=10 |pages=2598–2608 |doi=10.1172/JCI26662 |pmc=1236703 |pmid=16200192 }}</ref>

==== Treatment ====
In those extreme situations, in which kidney stones are too large to pass on their own, patients may seek removal. Most of these treatments involving kidney stone removal are done by a urologist; a physician who specializes in the organs of the [[urinary system]].<ref>{{Cite news|url=http://www.medicinenet.com/script/main/art.asp?articlekey=5916|title=Medical Definition of Urologist|work=MedicineNet|access-date=2017-04-23|language=en}}</ref> A common way of removal is shock wave lithotripsy, in which the urologist will shock the kidney stone into smaller pieces via laser, allowing these pieces to further pass through the urine on their own, as a normal case of kidney stones. Larger, more serious cases may demand Cystoscopy, Ureteroscopy, or Percutaneous Nephrolithotomy, in which the doctor will use a viewing tool or camera to locate the stone, and based on the size or situation, may either chose to continue with surgical removal, or use the shock wave lithotripsy treatment. Once the kidney stone(s) are successfully eliminated, the urologist will commonly suggest medication to prevent future recurrences.<ref name=":1" />