mphysema is a disease that destroys some alveolar walls and increases airspaces inside the lungs that provide less surface area for oxygen absorption from the atmosphere (Mannino, 2002). Airways and air sacs lose their flexibility making it harder for them to expand and contract. Symptoms include wheezing shortness of breath and chest tightness.

Asthma is the least common respiratory disease present in COPD relative to chronic bronchitis and emphysema. It is a chronic inflammatory disorder of the airway in which many cells and cellular elements play a role. Recurrent episode of wheezing, breathlessness and coughing are some signs and symptoms.

The American Thoracic Society (ATS) COPD guidelines composed definitions for asthma, chronic bronchitis, emphysema, COPD and airflow obstruction and classified eleven separate disorders, as seen in the figure below. These guideline also recognised COPD as a respiratory disease where irreversible airflow interference is the underlying aspect, allowing COPD to be more clearly identified. Below is a non-proportional Venn diagram clearly distinguishing the eleven separate disorders in patients and the ways in which they overlap.

(Gibson and Simpson, 2009)

CAUSE:

Normal lungs function by pulmonary ventilation where inhalation occurs that causes each air sac to fill with air, and exhalation causing them to deflate. External respiration then takes place where oxygen from the lungs is exchanged with carbon dioxide from the blood vessels surrounding the alveoli. The transport of respiratory gases proceeds this followed by internal respiration which involves the movement of oxygen from the blood vessels to the tissues and the movement of carbon dioxide from the tissues to the blood. When inhalation occurs, air from the atmosphere passes through the primary bronchus(trachea) followed by secondary bronchi, segmented bronch