COPD: chronic obstructive pulmonary disease; DLCO: diffusing capacity for carbon monoxide; FEV1: forced expiratory volume in one second; FVC: forced vital capacity; VC: vital capacity; ILD: interstitial lung disease.
* Bronchoprovocation testing uses a variety of challenges (eg, methacholine, mannitol, exercise, isocapnic hyperpnea) to assess airway hyperresponsiveness.
ΒΆ Causes of high DLCO include increased hemoglobin and increased pulmonary vascular blood volume (eg, right-to-left shunt, asthma, and obesity).