Editing Edema (section)

==Cause==
=== Heart ===
The pumping force of the [[human heart|heart]] should help to keep a normal pressure within the [[blood vessel]]s. But if the heart begins to fail (a condition known as [[congestive heart failure]]) the pressure changes can cause very severe water retention. In this condition water retention is mostly visible in the [[human leg|leg]]s, feet and [[ankle]]s, but water also collects in the [[lungs]], where it causes a chronic [[cough]]. This condition is usually treated with [[diuretics]]; otherwise, the water retention may cause breathing problems and additional stress on the heart.<ref name=":0">{{Cite journal|last1=Casu|first1=Gavino|last2=Merella|first2=Pierluigi|date=July 2015|title=Diuretic Therapy in Heart Failure – Current Approaches|journal=European Cardiology Review|volume=10|issue=1|pages=42–47|doi=10.15420/ecr.2015.10.01.42|issn=1758-3756|pmc=6159465|pmid=30310422}}</ref>

=== Kidneys ===
Another cause of severe water retention is [[kidney failure]], where the [[kidneys]] are no longer able to filter fluid out of the [[blood]] and turn it into [[urine]]. [[Kidney disease]] often starts with [[inflammation]], for instance in the case of diseases such as [[nephrotic syndrome]] or [[Systemic lupus erythematosus|lupus]]. This type of water retention is usually visible in the form of swollen [[human leg|leg]]s and [[ankle]]s.<ref>{{Cite web |title=Edema - Symptoms and causes |url=https://www.mayoclinic.org/diseases-conditions/edema/symptoms-causes/syc-20366493 |access-date=2022-07-19 |website=Mayo Clinic |language=en}}</ref>

=== Liver ===
[[Cirrhosis]] (scarring) of the liver is a common cause of edema in the legs and abdominal cavity.<ref>{{Cite web |title=Edema - Symptoms and causes |url=https://www.mayoclinic.org/diseases-conditions/edema/symptoms-causes/syc-20366493 |access-date=2022-12-23 |website=Mayo Clinic |language=en}}</ref>

=== Veins ===
Phlebetic lymphedema (or phlebolymphedema) is seen in untreated [[chronic venous insufficiency]] and is the most common type of edema (approx. 90%).<ref name=":1">{{Cite web |last1=Publishing |first1=Licorn |last2=Guiboles |date=2009-11-24 |title=The causes of edema in chronic venous insufficiency |url=https://www.phlebolymphology.org/the-causes-of-edema-in-chronic-venous/ |access-date=2023-09-01 |website=Servier - Phlebolymphology |language=en-US}}</ref> It is a combination venous/lymphatic disorder that originates in defective "leaky" veins that allows the blood to back flow ([[Chronic venous insufficiency|venous reflux]]), slowing the return of the blood to the heart ([[venous stasis]]). The venous pressure in the legs changes dramatically while standing compared to lying down. How much pressure there is depends on the person's height, in the average adult person, it is 8 mm Hg while lying down and 100 mm Hg while standing.<ref name=":2">{{Cite journal |last=Farrow |first=Wade |date=2010 |title=Phlebolymphedema-a common underdiagnosed and undertreated problem in the wound care clinic |journal=The Journal of the American College of Certified Wound Specialists |volume=2 |issue=1 |pages=14–23 |doi=10.1016/j.jcws.2010.04.004 |issn=1876-4983 |pmc=3601853 |pmid=24527138}}</ref>

In venous insufficiency, venous stasis results in abnormally high venous pressure (venous hypertension) and greater permeability of blood capillaries (capillary hyperpermeability), to drain the blood through the lymphatic system. The lymphatic system slowly removes excess fluid and proteins from the veins in the lower legs towards the upper body; however, as it is not as efficient as an unimpaired circulatory system, swelling (edema) is visible, particularly in the ankles and lower leg. The chronic increased fluid in the lymphatic system and capillary hyperpermeability causes an inflammatory response which leads to tissue fibrosis of both veins and lymphatic system, opening of arteriovenous shunts, all of which then worsens the condition in a vicious cycle.<ref name=":1" /><ref name=":2" />

=== Others ===
Swollen [[human leg|leg]]s, feet and [[ankle]]s are common in late [[pregnancy]]. The problem is partly caused by the weight of the [[uterus]] on the major [[vein]]s of the [[human pelvis|pelvis]]. It usually clears up after delivery of the baby, and is mostly not a cause for concern,<ref>{{cite web |url=http://www.merck.com/mmpe/sec18/ch259/ch259e.html |first1=R. Phillips  |last1=Heine |first2=Geeta K. |last2=Swamy |title=Lower-Extremity Edema During Late Pregnancy |work=[[The Merck Manual]] |access-date=9 August 2017}}</ref> though it should always be reported to a doctor.

Lack of exercise is another common cause of water retention in the legs. Exercise helps the leg [[vein]]s work against [[gravity]] to return [[blood]] to the [[human heart|heart]]. If [[blood]] travels too slowly and starts to pool in the [[human leg|leg]] [[vein]]s, the pressure can force too much fluid out of the [[human leg|leg]] [[capillary|capillaries]] into the tissue spaces. The [[capillary|capillaries]] may break, leaving small blood marks under the [[human skin|skin]]. The [[vein]]s themselves can become swollen, painful and distorted – a condition known as [[varicose vein]]s.<ref>{{cite book |title=Introductory Medical-Surgical Nursing |first1=Barbara Kuhn |last1=Timby |first2=Nancy E. |last2=Smith |year=2006 |edition=9th |location=Philadelphia |publisher=Lippincott Williams & Wilkins |page=[https://archive.org/details/introductorymedi00timb/page/488 488] |isbn=978-0-78178-032-2 |url=https://archive.org/details/introductorymedi00timb/page/488 }}</ref> [[Muscle]] action is needed not only to keep [[blood]] flowing through the [[vein]]s but also to stimulate the [[lymphatic system]] to fulfil its "overflow" function. Long-haul [[flight]]s, lengthy [[bed-rest]], immobility caused by [[disability]] and so on, are all potential causes of water retention. Even very small exercises such as rotating [[ankle]]s and wiggling [[toe]]s can help to reduce it.<ref>{{cite book |title=Lymphedema Management: The Comprehensive Guide for Practitioners |first=Joachim E. |last=Zuther |year=2005 |edition=1st |location=New York |publisher=[[Thieme Medical Publishers]] |page=222 |isbn=978-1-58890-284-9 |url=https://archive.org/details/lymphedemamanage00joac/page/222 }}</ref>

Certain [[medications]] are prone to causing water retention. These include [[estrogen]]s, thereby including drugs for [[hormone replacement therapy (menopause)|hormone replacement therapy]] or the [[combined oral contraceptive pill]],<ref>{{cite web |url=http://www.merck.com/mmpe/lexicomp/estrogens%20(conjugated-equine).html |title=Estrogens (Conjugated/Equine) |work=The Merck Manual |access-date=9 August 2017 |archive-url=https://web.archive.org/web/20071202133613/http://www.merck.com/mmpe/lexicomp/estrogens%20(conjugated-equine).html |archive-date=2 December 2007}}</ref> as well as [[non-steroidal anti-inflammatory drugs]] and [[beta-blockers]].<ref>{{cite web |url=http://www.webmd.com/hypertension-high-blood-pressure/hypertension-treatment-beta-blockers |title=Beta-Blockers for High Blood Pressure |work=[[WebMD]] |access-date=9 August 2017}}</ref>

[[Premenstrual water retention]], causing [[bloating]] and [[breast tenderness]], is common.<ref name="Copstead-KirkhornBanasik2014">{{cite book|author1=Lee-Ellen C. Copstead-Kirkhorn|author2=Jacquelyn L. Banasik|title=Pathophysiology|url=https://books.google.com/books?id=i7jwAwAAQBAJ&pg=PA660|date=25 June 2014|publisher=Elsevier Health Sciences|isbn=978-0-323-29317-4|pages=660–}}</ref><ref name="pmid19099613">{{cite journal | vauthors = Farage MA, Neill S, MacLean AB | title = Physiological changes associated with the menstrual cycle: a review | journal = Obstet Gynecol Surv | volume = 64 | issue = 1 | pages = 58–72 | year = 2009 | pmid = 19099613 | doi = 10.1097/OGX.0b013e3181932a37 | s2cid = 22293838 }}</ref><ref name="Pooler2009">{{cite book|author=Charlotte Pooler|title=Porth Pathophysiology: Concepts of Altered Health States|url=https://books.google.com/books?id=2-MFXOEG0lcC&pg=PA1075|date=1 October 2009|publisher=Lippincott Williams & Wilkins|isbn=978-1-60547-781-7|pages=1075, 1107}}</ref>