Chronic obstructive pulmonary disease (COPD) is one of major non-communicable diseases affecting millions of people around the world. It is slowly developing and progressing disease characterized by mostly irreversible pathophysiological changes resulting in gradual loss of pulmonary function. It presents with different phenotypes associated with specific pathophysiological changes in individual patients. Diagnostic evaluation of COPD traditionally includes pulmonary function tests (PFT) using spirometry. Spirometry is considered to be the internationally accepted gold standard diagnostic method during evaluation for COPD. Although spirometry is commonly used to diagnose COPD, it may sometime lack adequate sensitivity to detect fine pathophysiological changes associated with particular phenotypes of COPD. Development and use of new alternate diagnostic methods could improve not only diagnosis of COPD, but also optimize the management and treatments.