Editing Blood plasma (section)

==Volume==
{{multiple image|align=left|direction=vertical
| image1 = Reference ranges for blood tests - by mass.svg| width1 = 550
| caption1 = [[Reference ranges for blood tests]], showing normal mass concentration of blood plasma constituents
| image2 = Reference ranges for blood tests - by molarity.png| width2 = 550
| caption2 = The same information, shown in molarity rather than mass
}}

Blood plasma volume may be expanded by or drained to [[extravascular fluid]] when there are changes in [[Starling forces]] across capillary walls. For example, when [[blood pressure]] drops in [[Shock (circulatory)|circulatory shock]], Starling forces drive fluid into the [[interstitium]], causing [[Fluid compartments#Third spacing|third spacing]].<ref>{{cite journal | vauthors = Dargent A, Dumargne H, Labruyère M, et al | title = Role of the interstitium during septic shock: a key to the understanding of fluid dynamics? | journal = Intensive Care | volume = 11 | issue = 44 | date = October 2023 | page = 44 | doi = 10.1186/s40560-023-00694-z | doi-access = free| pmid = 37817235 | pmc = 10565984 }}</ref>

Standing still for a prolonged period will cause an increase in [[transcapillary hydrostatic pressure]]. As a result, approximately 12% of blood plasma volume will cross into the [[extravascular compartment]]. This '''plasma shift''' causes an increase in [[hematocrit]], [[serum total protein]], [[blood viscosity]] and, as a result of increased concentration of [[coagulation factors]], it causes [[orthostatic hypercoagulability]].<ref>{{cite journal | vauthors = Masoud M, Sarig G, Brenner B, Jacob G | title = Orthostatic hypercoagulability: a novel physiological mechanism to activate the coagulation system | journal = Hypertension | volume = 51 | issue = 6 | pages = 1545–1551 | date = June 2008 | pmid = 18413485 | doi = 10.1161/HYPERTENSIONAHA.108.112003 | doi-access = free }}</ref>