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hyperventilation hy·per·ven·ti·la·tion (hī'pər-věn'tl-ā'shən)
Abnormally fast or deep respiration resulting in the loss of carbon dioxide from the blood, thereby causing a decrease in blood pressure and sometimes fainting.
sustained abnormal increase in breathing. During hyperventilation the rate of removal of carbon dioxide from the blood is increased. As the partial pressure of carbon dioxide in the blood decreases, respiratory alkalosis, characterized by decreased acidity or increased alkalinity of the blood, ensues. In turn, alkalosis causes constriction of the small blood vessels that supply the brain. Reduced blood supply to the brain can cause a variety of symptoms, including light-headedness and tingling of the fingertips. Severe hyperventilation can cause transient loss of consciousness.