chronic obstructive pulmonary disease is a common preventable and treatable disease characterized by persistent airflow limitation that is usually progressive. The diagnosis requires an evidence of obstructive pattern by spirometry measured before and after bronchodilators.
The degree of reversibility of airflow obstruction differs between patients, and does not predict the response to bronchodilator therapy. It can be seen in terms of forced vital capacity (FVC) or forced expiratory volume in the first second (FEV1),or Inspiratory capacity (IC) or residual volume (RV).
