My bmi 29-30. pulmonary function test show: fvc 39%,fev1 39%, their ratio 78%, rv 151%, tlc 90%, their ratio 49%, dlco 81%, dlco/va ratio 91%, is this asthma, and how bad? mild, moderate, severe?

Asthma is a pattern of airway spasm triggered by events/agents causing acute reduction in air flow. If you have such episodes you may have asthma. Poor lung function tests mean you have poor lung mechanics for one or more reasons. The doc who ordered the study and knows your case can decide what your function represents. The posted numbers do not provide enough information to define the issue.

The DLCP is normal. The test indicated possible overinflation, air trapping and reduced airflow in larger airways. A bronchodilator challenge test is recommended and the FEF 25/75 is available and please provide this information. Asthma is also a clinical diagnosis and more information may be provided with a HT virtual consult. So you have a smoking history? Exposure history? allergies?