Chronic obstructive pulmonary disease (COPD) is a teep o obstructive buff disease chairacterised bi lang-term puir airflow. The main symptoms include shortness o breath an coch wi sputum production. COPD is a progressive disease, meanin it teepically worsens ower time. Eventually everyday activities, such as walkin up stairs, acome difficult. Chronic bronchitis an emphysema are aulder terms uised for different teeps o COPD. The term ""chronic bronchitis"" is still uised tae define a productive coch that is present for at least three months each year for twa years.