Hyperventilation

An abnormally increased rate and depth of alveolar ventilation leading to excessive CO₂ elimination, reduced arterial PaCO₂ (<4.8 kPa or 35 mmHg), and consequent respiratory alkalosis. Possible causes are anxiety, fear, stress, asthma, COPD, heart failure, pulmonary embolism, diabetic ketoacidosis, sepsis, bleeding, pain, fever, high altitude, amphetamine, pregnancy, and strenuous exercise.