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Hypoxemia (or hypoxaemia in British English) is an abnormally low level of oxygen in the blood.〔 More specifically, it is oxygen deficiency in arterial blood. Hypoxemia has many causes, often respiratory disorders, and can cause tissue hypoxia as the blood is not supplying enough oxygen to the body. ==Definition== ''Hypoxemia'' refers to low oxygen in the blood, and the more general term ''hypoxia'' is an abnormally low oxygen content in any tissue or organ, or the body as a whole.〔 Hypoxemia can cause hypoxia (hypoxemic hypoxia), but hypoxia can also occur via other mechanisms, such as anemia.〔 Robert J. Mason, V. Courtney Broaddus, Thomas R. Martin, Talmadge E. King, Dean E. Schraufnagel, John F. Murray and Jay A. Nadel (eds.) (2010) Murray & Nadel's Textbook of Respiratory Medicine, 5th ed. Philadelphia: Saunders Elsevier. ISBN 1-4160-4710-7. 〕 Informally, ''hypoxemic hypoxia'' is sometimes called ''hypoxic hypoxia''. Hypoxemia is usually defined in terms of reduced partial pressure of oxygen (mm Hg) in arterial blood, but also in terms of reduced content of oxygen (ml oxygen per dl blood) or percentage saturation of hemoglobin (the oxygen binding protein within red blood cells) with oxygen, which is either found singly or in combination.〔 Morris, Alan; Kanner, Richard; Crapo, Robert; Gardner, Reed. (1984) ''Clinical Pulmonary Function Testing. A manual of uniform laboratory procedures'', 2nd ed.〕 While there is general agreement that an arterial blood gas measurement which shows that the partial pressure of oxygen is lower than normal constitutes hypoxemia,〔〔 there is less agreement concerning whether the oxygen content of blood is relevant in determining hypoxemia. This definition would include oxygen carried by hemoglobin. The oxygen content of blood is thus sometimes viewed as a measure of tissue delivery rather than hypoxemia.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Hypoxemia」の詳細全文を読む スポンサード リンク
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