Editing Blood pressure (section)

==Systemic venous pressure==
{{Non-systemic blood pressures}}
Blood pressure generally refers to the arterial pressure in the [[systemic circulation]]. However, measurement of pressures in the venous system and the [[Pulmonary circulation|pulmonary vessels]] plays an important role in [[intensive care medicine]] but requires invasive measurement of pressure using a [[catheter]].

Venous pressure is the vascular pressure in a [[vein]] or in the [[atrium (anatomy)|atria of the heart]]. It is much lower than arterial pressure, with common values of 5&nbsp;mmHg in the [[right atrium]] and 8&nbsp;mmHg in the left atrium.

Variants of venous pressure include:
* [[Central venous pressure]], which is a good approximation of right atrial pressure,<ref name="urlCentral Venous Catheter Physiology">{{cite web |url=http://www.healthsystem.virginia.edu/internet/anesthesiology-elective/cardiac/cvcphys.cfm |title=Central Venous Catheter Physiology |access-date=2009-02-27 |url-status=dead |archive-url=https://web.archive.org/web/20080821165806/http://www.healthsystem.virginia.edu/internet/anesthesiology-elective/cardiac/cvcphys.cfm |archive-date=2008-08-21 }}</ref> which is a major determinant of right ventricular end diastolic volume. (However, there can be exceptions in some cases.)<ref name="pmid12533747">{{cite journal | vauthors = Tkachenko BI, Evlakhov VI, Poyasov IZ | title = Independence of changes in right atrial pressure and central venous pressure | journal = Bulletin of Experimental Biology and Medicine | volume = 134 | issue = 4 | pages = 318–320 | date = October 2002 | pmid = 12533747 | doi = 10.1023/A:1021931508946 | s2cid = 23726657 }}</ref>
* The [[jugular venous pressure]] (JVP) is the indirectly observed pressure over the venous system. It can be useful in the differentiation of different forms of [[heart disease|heart]] and [[lung disease]].
* The [[portal venous pressure]] is the blood pressure in the [[portal vein]]. It is normally 5–10&nbsp;mmHg<ref>{{cite web |url=http://www.emedicine.com/med/byname/esophageal-varices.htm |title=Esophageal Varices : Article Excerpt by: Samy A Azer |publisher=eMedicine |access-date=2011-08-22 |archive-date=2008-10-07 |archive-url=https://web.archive.org/web/20081007113712/http://www.emedicine.com/med/byname/Esophageal-Varices.htm |url-status=live }}</ref>