hyperventilation

from WordNet (r) 3.0 (2006)

hyperventilation
    n 1: an increased depth and rate of breathing greater than
         demanded by the body needs; can cause dizziness and
         tingling of the fingers and toes and chest pain if
         continued

from The Collaborative International Dictionary of English v.0.48

hyperventilation \hyperventilation\ n.
   1. The act or process of hyperventilating; breathing rapidly
      and deeply.
      [PJC]

   2. (Med.) A condition in which alveolar carbon dioxide
      concentration is markedly lower than normal, usually due
      to breathing rapidly and deeply.
      [PJC]