This breathing test can detect COPD ... FVC (FEV1/FVC). A low percentage confirms airflow obstruction, which can then be used to help determine what might cause that airflow obstruction: COPD ...

A ratio of your FEV1/FVC needs to be less than 0.7 for a diagnosis of COPD. Doctors grade your spirometry results from grade 1 (least severe) to grade 4 (most severe). In the old system ...