Here are the most common disease of respiratory system in Malaysia:
1) Chronic Obstructive Pulmonary Disease
2) Tuberculosis
3) Pneumonia
We decide to discuss about Chronic Obstructive Pulmonary Disease first:
Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease (COPD) is a common cause of illness in the community associated mainly with cigarette smoking. It is a progressive disease with considerable morbidity and mortality.
Chronic obstructive pulmonary disease is a condition characterised by persistent airflow obstruction, which is slowly progressive. It may be partially reversible and there may be features of airway hyperreactivity. Traditionally, it comprises chronic bronchitis and emphysema.
Chronic bronchitis is defined by the presence of increased bronchial secretions with chronic cough and expectoration on most days for at least 3 months a year in two consecutive years.
Emphysema is defined anatomically by permanent destructive enlargement of airspaces distal to the terminal bronchioles without obvious fibrosis.
Pathology
a) Chronic bronchitis
Hyperplasia of the secretory cells and mucous gland enlargement are the histological hallmarks of chronic bronchitis, and these are the tissue correlates of increased sputum production. These changes are due to repeated irritation by pollutants and infections. Airway wall inflammation, stenosis and distortion due to fibrosis may also be present. The small bronchi and bronchioles are the main sites of the increased resistance to airflow.
b) Emphysema
Two main forms of emphysema are described.Centriacinar emphysema is characterised by focal destruction restricted to respiratory bronchioles and the central portion of an acinus, surrounded by relatively normal lung. Panacinar emphysema involves destruction of all the air spaces supplied by the terminal bronchiole. The current view is that emphysema occurs as a result of an imbalance between proteases and anti-protease resulting in a relative increase in proteases and resultant destruction of lung tissue.