[Stage and prognosis of COPD].

Clinical stages of chronic obstructive pulmonary disease(COPD) have been described in the guideline by American Thoracic Society(ATS), European Respiratory Society(ERS), and Japanese Respiratory Society. Recently, the clinical stage in GOLD(Global Initiative Obstructive Lung Disease) was also published in the guideline as an international standard. Although severity or clinical stages of COPD in ATS, ERS, and JRS guidelines is determined by only % predicted FEV1.0/FVC(%FEV1.0), GOLD guideline added clinical symptoms to %FEV1.0 for determining clinical stages of COPD. Prognosis is also correlated with %FEV1.0 in COPD patients. Prognosis of COPD patients shows a clear decline in proportion to that of %FEV1.0. However, pulmonary circulation disorder also affects the prognosis of COPD. Pulmonary hypertension is often found in severe COPD.