gave a fruitful presentation on “Acute Exacerbation of COPD , he defined COPD and its pathophysiology as well as the definition of exacerbations according to the ATS and ERS definitions, the impact of Acute Exacerbations of COPD as well as the severity of COPD and its causes as he mentioned the main causes is “Airway infections” e.g. streptocoscus pneumonia, Moraxella Catarhalis & Haemophilus Influenza. He also presented the preventive measures that should be taken in consideration with COPD patients.