The importance of the assessment of pulmonary function in COPD.

Spirometry is the gold standard for making the diagnosis of COPD. It should be performed in every case of suspected COPD. Other pulmonary functions, such as lung volumes, can give insight into physiologic consequences of COPD, such as hyperinflation. Pulmonary function testing can also aid in assessing the severity of disease and in managing the disease after diagnosis is made.