- 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. resulting from a decreased concentration of functional hemoglobin or a reduced number of erythrocytes; it is caused by hemorrhage or anemia of various types, or by poisoning with carbon monoxide, nitrites, or chlorates.- diffusion h. abrupt transient decrease in alveolar oxygen tension when room air is inhaled at the conclusion of a nitrous oxide anesthesia, because nitrous oxide diffusing out of the blood dilutes the alveolar oxygen.- hypoxic h. h. resulting from a defective mechanism of oxygenation in the lungs; may be caused by a low tension of oxygen, abnormal pulmonary function or respiratory obstruction, or a right-to-left shunt in the heart.- ischemic h. tissue h. characterized by tissue oligemia and caused by arterial or arteriolar obstruction or vasoconstriction.- stagnant h. tissue h. characterized not by tissue oligemia (tissue blood volume being normal or even increased), but by intravascular stasis due to impairment of venous outflow or (in some instances) to decreased arterial inflow.
* * *hyp·ox·ia hip-'äk-sē-ə, hī-'päk- n a deficiency of oxygen reaching the tissues of the bodyhyp·ox·ic -sik adj
* * *n.
* * *hy·pox·ia (hi-pokґse-ə) reduction of oxygen supply to tissue below physiological levels despite adequate perfusion of the tissue by blood. Cf. anoxia. hypoxic adj
Medical dictionary. 2011.