What is Oxygen saturation?
'''Oxygen saturation''' or '''dissolved oxygen''' (DO) is a relative [[measure]] of the amount of [[oxygen]] (as O<sub>2</sub>) which is [[dissolve]]d in a given medium. It can be measured with an oxygen [[sensor]]. The standard unit of oxygen saturation is percent (%). [[Fish]], [[invertebrate]]s, [[plant]]s, and [[aerobic]] [[bacteria]] all need oxygen (dissolved in water) for [[respiration]].<ref>''Ecology and classification of North American freshwater invertebrates'': James H. Thorp; Alan P. Covich (eds) 2010. Amsterdam; Boston: Academic Press, p32.</ref> In [[medicine]], oxygen saturation refers to ''oxygenation''. This means when [[oxygen]] molecules ({{chem|O|2}}) enter the [[Tissue (biology)|tissues]] of the body. Normal arterial blood oxygen saturation levels in humans are 95–100 percent. If the level is below 90 percent, it is considered low and called ''hypoxemia''.<ref>{{cite web|title=Hypoxemia (low blood oxygen)|url=http://www.mayoclinic.com/health/hypoxemia/MY00219|work=Mayo Clinic|publisher=mayoclinic.com|access-date=6 June 2013}}</ref> == References == {{reflist}} [[Category:Physiology]] [[Category:Oxygen]] [[Category:Environmental chemistry]] {{biology-stub}}