Acute exacerbation of COPD is among the most frequent reasons for hospitalisation. Approximately 4% of the general population in the western world is admitted with an acute respiratory disease at least once a year and nearly one fifth of hospital visits is due to acute exacerbation of COPD. Early identiﬁcations and management of AE-COPD is an important issue in clinical practice. AE-COPD is accompanied with various worsening respiratory symptoms and deterioration in lung function. Also the frequency and severity of attacks is associated with increased mortality.