- hypoxia [hī päk′sē ə, hipäk′sē ə]n.an abnormal condition resulting from a decrease in the oxygen supplied to or utilized by body tissuehypoxicadj.
* * *hy·pox·i·a (hī-pŏkʹsē-ə, hĭ-) n.Deficiency in the amount of oxygen reaching body tissues.hy·poxʹic adj.
* * *Condition in which tissues are starved of oxygen.The extreme is anoxia (absence of oxygen). There are four types: hypoxemic, from low blood oxygen content (e.g., in altitude sickness); anemic, from low blood oxygen-carrying capacity (e.g., in carbon monoxide poisoning); distributive, from low blood flow (e.g., generally in shock or locally in atherosclerosis); and histotoxic, from poisoning (e.g., with cyanide) that keeps cells from using oxygen. If not reversed quickly, hypoxia can lead to necrosis (tissue death), as in heart attack.
* * *condition of the body in which the tissues are starved of oxygen. In its extreme form, where oxygen is entirely absent, the condition is called anoxia. There are four types of hypoxia: (1) the hypoxemic type, in which the oxygen pressure in the blood going to the tissues is too low to saturate the hemoglobin; (2) the anemic type, in which the amount of functional hemoglobin is too small, and hence the capacity of the blood to carry oxygen is too low; (3) the stagnant type, in which the blood is or may be normal but the flow of blood to the tissues is reduced or unevenly distributed; and (4) the histotoxic type, in which the tissue cells are poisoned and are therefore unable to make proper use of oxygen. Diseases of the blood, the heart and circulation, and the lungs may all produce some form of hypoxia.The hypoxemic type of hypoxia is due to one of two mechanisms: (1) a decrease in the amount of breathable oxygen—often encountered in pilots, mountain climbers, and people living at high altitudes—due to the reduced barometric pressure (see altitude sickness), or (2) cardiopulmonary failure in which the lungs are unable to efficiently transfer oxygen from the alveoli to the blood.In the case of anemic hypoxia, either the total amount of hemoglobin is too small to supply the body's oxygen needs, as in anemia or after severe bleeding, or hemoglobin that is present is rendered nonfunctional. Examples of the latter case are carbon monoxide poisoning and metho-globinuria, in both of which the hemoglobin is so altered by toxic agents that it becomes unavailable for oxygen transport, and thus of no respiratory value.Stagnant hypoxia, in which blood flow through the capillaries is insufficient to supply the tissues, may be general or local. If general, it may result from heart disease that impairs the circulation, impairment of veinous return of blood, or trauma that induces shock. Local stagnant hypoxia may be due to any condition that reduces or prevents the circulation of the blood in any area of the body. Examples include Raynaud's disease (Raynaud syndrome) and Buerger's disease, which restrict circulation in the extremities; the application of a tourniquet to control bleeding; ergot poisoning; exposure to cold; and overwhelming systemic infection with shock.In histotoxic hypoxia the cells of the body are unable to use the oxygen, although the amount in the blood may be normal and under normal tension. Although characteristically produced by cyanide, any agent that decreases cellular respiration may cause it. Some of these agents are narcotics, alcohol, formaldehyde, acetone, and certain anesthetic agents.
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hypoxia — 1941, from HYPO (Cf. hypo ) + OXYGEN (Cf. oxygen). Related: Hypoxic … Etymology dictionary
hypoxia — [hī päk′sē ə, hipäk′sē ə] n. [ModL: see HYPO & OXY 1 & IA] an abnormal condition resulting from a decrease in the oxygen supplied to or utilized by body tissue hypoxic adj … English World dictionary
Hypoxia — Infobox Disease Name = Hypoxia Caption = DiseasesDB = ICD10 = ICD9 = ICD9|799.02 ICDO = OMIM = MedlinePlus = eMedicineSubj = eMedicineTopic = eMedicine mult = MeshID = Hypoxia literally means a deficiency in oxygen. It can refer to:* Hypoxia… … Wikipedia
hypoxia — A state of oxygen deficiency in the body sufficient to cause an impairment of body function. It is caused by the reduction in partial pressure of oxygen, inadequate oxygen transport, or the inability of the tissue to use oxygen. In flying,… … Aviation dictionary
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hypoxia — A condition in which there is a decrease in the oxygen supply to a tissue. In cancer treatment, the level of hypoxia in a tumor may help predict the response of the tumor to the treatment … English dictionary of cancer terms
hypoxia — noun Etymology: New Latin Date: 1941 a deficiency of oxygen reaching the tissues of the body • hypoxic adjective … New Collegiate Dictionary
hypoxia — Condition in which there is an abnormally low level of oxygen in the blood and tissues … Dictionary of molecular biology
hypoxia — noun a) A condition in which tissues (especially the blood) are deprived of an adequate supply of oxygen; anoxia b) A reduced concentration of dissolved oxygen in an aquatic environment. See Also: normoxia … Wiktionary
Hypoxia — Concentration of oxygen in arterial blood that is less than normal. Anoxia refers to complete lack of oxygen. * * * Decrease below normal levels of oxygen in inspired gases, arterial blood, or tissue, short of anoxia. [hypo + oxygen] anemic h. h … Medical dictionary