Editing Edema (section)

==Signs and symptoms==
{{More citations needed section|date=December 2024}}

===Specific area===
An edema will occur in specific organs as part of inflammations, [[Tendonopathy|tendinitis]] or [[pancreatitis]], for instance. Certain organs develop edema through tissue specific mechanisms. Examples of edema in specific organs:
* [[Peripheral edema]] ("dependent" edema of legs) is extracellular fluid accumulation in the lower extremities caused by the effects of gravity, and occurs when fluid pools in the lower parts of the body, including the feet, legs, or hands.  This often occurs in immobile patients, such as paraplegics or quadriplegics, pregnant women, or in otherwise healthy people due to [[hypervolemia]] or maintaining a standing or seated posture for an extended period of time. It can occur due to diminished venous return of blood to the heart due to congestive heart failure or [[pulmonary hypertension]]. It can also occur in patients with increased hydrostatic venous pressure or decreased oncotic venous pressure, due to obstruction of lymphatic or venous vessels draining the lower extremity. Certain drugs (for example, amlodipine) can cause pedal edema.
* [[Cerebral edema]] is extracellular fluid accumulation in the brain.<ref name="IQ2016" /> It can occur in toxic or abnormal metabolic states and conditions such as systemic lupus or reduced oxygen at high altitudes. It causes drowsiness or loss of consciousness, leading to [[brain herniation]] and death.
* [[Pulmonary edema]] occurs when the pressure in blood vessels in the lung is raised because of obstruction to the removal of blood via the pulmonary veins. This is usually due to failure of the left ventricle of the heart. It can also occur in altitude sickness or on inhalation of toxic chemicals. Pulmonary edema produces shortness of breath. [[Pleural effusion]]s may occur when fluid also accumulates in the [[pleural]] cavity.
* Edema may also be found in the cornea of the eye with [[glaucoma]], severe [[conjunctivitis]], [[keratitis]], or after surgery. Affected people may perceive coloured haloes around bright lights.
* Edema surrounding the eyes is called [[periorbital edema]] (puffy eyes) . The periorbital tissues are most noticeably swollen immediately after waking, perhaps as a result of the gravitational redistribution of fluid in the horizontal position.
* Common appearances of [[cutaneous]] edema are observed with [[mosquito]] bites, [[spider]] bites, bee stings ([[wheal and flare]]), and skin contact with certain plants such as [[poison ivy]] or [[western poison oak]],<ref>{{cite web |first=C. Michael |last=Hogan |year=2008 |url=http://globaltwitcher.auderis.se/artspec_information.asp?thingid=82914 |title=Western poison-oak: Toxicodendron diversilobum |archive-url=https://web.archive.org/web/20090721044257/http://globaltwitcher.auderis.se/artspec_information.asp?thingid=82914 |archive-date=July 21, 2009  |website=GlobalTwitcher |editor-first=Nicklas |editor-last=Strömberg}}</ref> the latter of which are termed ''[[contact dermatitis]]''.
* Another cutaneous form of edema is [[myxedema]], which is caused by increased deposition of [[connective tissue]]. In myxedema (and a variety of other rarer conditions) edema is caused by an increased tendency of the tissue to hold water within its extracellular space. In myxedema, this is due to  an increase in hydrophilic carbohydrate-rich molecules (perhaps mostly [[hyaluronin]]) deposited in the tissue matrix. Edema forms more easily in dependent areas in the elderly (sitting in chairs at home or on aeroplanes) and this is not well understood. Estrogens alter body weight in part through changes in tissue water content. There may be a variety of poorly understood situations in which transfer of water from tissue matrix to lymphatics is impaired because of changes in the hydrophilicity of the tissue or failure of the 'wicking' function of terminal lymphatic capillaries.
* Myoedema is localized mounding of muscle tissue due to percussive pressure, such as flicking the relaxed muscle with the forefinger and thumb. It produces a mound, visible, firm and non-tender at the point of tactile stimulus approximately 1-2 seconds after stimulus, subsiding back to normal after 5-10 seconds. It is a sign in hypothyroid myopathy, such as [[Hoffmann syndrome]].<ref>{{Cite journal |last1=Vignesh |first1=G |last2=Balachandran |first2=Karthik |last3=Kamalanathan |first3=Sadishkumar |last4=Hamide |first4=Abdoul |date=2013 |title=Myoedema: A clinical pointer to hypothyroid myopathy |journal=Indian Journal of Endocrinology and Metabolism |volume=17 |issue=2 |pages=352 |doi=10.4103/2230-8210.109672 |issn=2230-8210 |pmc=3683223 |pmid=23776921 |doi-access=free }}</ref>
* In [[lymphedema]], abnormal removal of interstitial fluid is caused by failure of the [[lymphatic system]]. This may be due to obstruction from, for example, pressure from a [[cancer]] or enlarged [[lymph nodes]], destruction of lymph vessels by [[radiotherapy]], or infiltration of the lymphatics by infection (such as [[Podoconiosis|elephantiasis]]). It is most commonly due to a failure of the pumping action of muscles due to immobility, most strikingly in conditions such as multiple sclerosis, or paraplegia. It has been suggested that the edema that occurs in some people following use of aspirin-like cyclo-oxygenase inhibitors such as ibuprofen or indomethacin may be due to inhibition of lymph heart action.

{{Gallery
|height=200
|width =150
|whitebg=no
|style = margin-top:1em;
|Image:Geschwollener menschlicher Fuß.JPG|Foot two weeks post-surgery.
|Image:MyParonychia.jpg|The [[distal phalanx]] of the right finger exhibits edema due to [[acute paronychia]].
|Image:SeverePedalEdema.jpg|Severe edema in the legs and feet.
}}

=== Generalized ===
A rise in [[hydrostatic pressure]] occurs in cardiac failure. A fall in osmotic pressure occurs in [[nephrotic syndrome]] and [[liver failure]].<ref name="pmid8790586">{{cite journal |last= Renkin |first=EM | title = Cellular aspects of transvascular exchange: a 40-year perspective | journal = Microcirculation | volume = 1 | issue = 3 | pages = 157–67 | year = 1994 | pmid = 8790586 | doi = 10.3109/10739689409148270 | s2cid = 28046134 }}</ref>

Causes of edema that are generalized to the whole body can cause edema in multiple organs and peripherally. For example, severe heart failure can cause [[pulmonary edema]], pleural effusions, [[ascites]] and [[peripheral edema]]. Such severe systemic edema is called [[anasarca]]. In rare cases, a [[parvovirus B19]] infection may cause generalized edemas.<ref name="pmid23472922">{{cite journal |vauthors=Wiggli B, Imhof E, Meier CA, Laifer G | title = Water, water, everywhere. Acute parvovirus B19 infection | journal = Lancet | volume = 381 | issue = 9868 | pages = 776 | year = 2013 | pmid = 23472922 | doi = 10.1016/S0140-6736(12)61894-7 | s2cid = 19300719 }}</ref>

Although a low plasma [[oncotic pressure]] is widely cited for the edema of nephrotic syndrome, most physicians note that the edema may occur before there is any significant protein in the urine ([[proteinuria]]) or fall in plasma protein level. Most forms of nephrotic syndrome are due to biochemical and structural changes in the basement membrane of capillaries in the kidney glomeruli, and these changes occur, if to a lesser degree, in the vessels of most other tissues of the body. Thus the resulting increase in permeability that leads to protein in the urine can explain the edema if all other vessels are more permeable as well.<ref name="pmid9185099">{{cite journal |vauthors=Palmer BF, Alpern RJ | title = Pathogenesis of edema formation in the nephrotic syndrome | journal = Kidney Int. Suppl. | volume = 59 | pages = S21–7 | year = 1997 | pmid = 9185099 }}</ref>

As well as the previously mentioned conditions, edemas often occur during the late stages of pregnancy in some women. This is more common with those of a history of pulmonary problems or poor circulation also being intensified if arthritis is already present in that particular woman. Women who already have arthritic problems most often have to seek medical help for pain caused from over-reactive swelling. Edemas that occur during pregnancy are usually found in the lower part of the leg, usually from the calf down.

[[Hydrops fetalis]] is a condition in a baby characterized by an accumulation of fluid in at least two body compartments.