Do i have emphysema? 28 10 pack years. constant sob. anxiety. pft normal with very low dlco. smoked before test. dr says asthma. what other causes?

Low DLCO: In asthma FEV1 is < 80% w/ FEV1/FVC ratio preserved, In COPD FEV1/FVC ratio is <0.7, FEV1is normal or low depending on stage of COPD. Low DLCO seen in fibrosis, vasculitis, emphysema- alveolar ( gas exchange ) area reduced due to destruction. FVC is low in restrictive disease. Smoking can worsen results of the test. If DLCO is low one would expect low FEV1/FVC unless intersitial f/u/doc