hyperventilation

breathing at an abnormally rapid rate when at rest, which may be a response to stress and, if not checked, results in unconsciousness because the concentration of carbon dioxide in the BLOOD falls. If the carbon dioxide level in the blood is abnormally high, because of impaired gas exchange in the LUNGS , e.g. in pulmonary OEDEMA and PNEUMONIA , hyperventilation may occur. (See also HYPOVENTILATION .)