Editing Diuresis (section)

== Osmotic diuresis ==
'''Osmotic diuresis''' is the increase of [[urination]] rate caused by the presence of certain substances in the [[proximal tubule]] (PCT) of the [[kidney]]s.<ref>{{Cite book |last=Ganong |first=William F. |url=https://books.google.com/books?id=OLa8vDBXDD4C&q=%22Osmotic+diuresis%22&pg=PA719 |title=Review of Medical Physiology |publisher=[[McGraw-Hill Education|McGraw-Hill Professional]] |year=2005 |isbn=978-0-07-144040-0 |page=719}}</ref> The excretion occurs when substances such as glucose enter the [[Nephron#Renal tubule|kidney tubules]] and cannot be reabsorbed (due to a pathological state or the normal nature of the substance). The substances cause an increase in the [[osmotic pressure]] within the tubule, causing retention of water within the lumen, and thus reduces the reabsorption of water, increasing urine output (i.e., diuresis). The same effect can be seen in therapeutics such as [[mannitol]], which is used to increase urine output and decrease extracellular fluid volume.{{citation needed|date=April 2021}}

Substances in the circulation can also increase the amount of circulating fluid by increasing the osmolarity of the blood. This has the effect of pulling water from the [[Extracellular fluid#Interstitial fluid|interstitial]] space, making more water available in the blood, and causing the kidney to compensate by removing it as urine. In [[hypotension]], [[colloid]]s are used often intravenously to increase circulating volume in themselves, but as they exert a certain amount of osmotic pressure, water is therefore also moved, further increasing circulating volume. As blood pressure increases, the kidney removes the excess fluid as urine. [[Sodium]], [[chloride]] and [[potassium]] are excreted in osmotic diuresis, originating from [[Diabetes|diabetes mellitus]] (DM). Osmotic diuresis results in [[dehydration]] from [[polyuria]] and the classic [[polydipsia]] (excessive thirst) associated with DM.<ref>{{Cite web |title=Osmotic Diuresis - an overview |url=https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/osmotic-diuresis |access-date=March 4, 2024 |website=ScienceDirect}}</ref>