Abnormal DLCO Increased DLCO 2015-09-24T19:00:25Z Increased diffusing capacity UMLS:C4073174 Factors that can increase the DLCO include polycythaemia, asthma (can also have normal DLCO) and increased pulmonary blood volume as occurs in exercise. Other factors are left to right intracardiac shunting, and alveolar hemorrhage. Increased ability of the lungs to transfer gas from inspired air to the bloodstream as measured by the diffusing capacity of the lungs for carbon monoxide (DLCO) test.