Table 3.

Interpreting abnormal, unadjusted values for diffusing capacity of the lung for carbon monoxide

Decreased DlCO Plus Airflow Obstruction	Decreased DlCO Plus Restrictive Pattern	Decreased DlCO with Normal Spirometry and Lung Volumes	Increased DlCO
Emphysema	Idiopathic pulmonary fibrosis	Pulmonary vascular diseases	Asthma
Lymphangioleiomyomatosis	Asbestosis	Early diffuse parenchymal lung disease	Obesity
Severe cystic fibrosis	Other diffuse parenchymal lung diseases	Anemia	Left-to-right shunt
	Pulmonary edema	Increased carboxyhemoglobin	Pulmonary hemorrhage
			Polycythemia

Definition of abbreviation: Dl_CO = diffusing capacity of the lung for carbon monoxide.