Table 1.

Causes of hypocapnia

Hypoxemia	Altitude, pulmonary disease
Pulmonary disorders	Pneumonia, interstitial pneumonitis, fibrosis, edema, pulmonary emboli, vascular disease, bronchial asthma, pneumothorax
Cardiovascular system disorders	Congestive heart failure, hypotension
Metabolic disorders	Acidosis (diabetic, renal, lactic), hepatic failure
Central nervous system disorders	Psychogenic/anxiety hyperventilation, central nervous system infection, central nervous system tumors
Drug induced	Salicylates, methylxanthines, β-adrenergic agonists, progesterone
Miscellaneous	Fever, sepsis, pain, pregnancy