COPD or Chronic Obstructive Pulmonary Disease is a lung disease such as emphysema, chronic bronchitis and bronchiectasis that prevents airways from working properly. The bronchioles lose their shape and become clogged with mucus. The walls of alveoli break down, thus forming fewer but larger alveoli. Air sacs gradually lose their ability to inflate and deflate. Each of these factors contribute to the airway losing elasticity and becoming clogged with mucus making it difficult to breathe thus not obtaining enough oxygen.