Disorders of Respiratory System

Asthma is a condition in which the bronchi and bronchioles become narrowed and inflamed, causing difficulty in breathing; it is commonly triggered by allergens such as dust, certain drugs, pollen, and foods like fish or prawns. Emphysema is a chronic, progressive breathlessness caused by the gradual breakdown of the thin alveolar walls, which reduces the total surface area available for gas exchange; it is most often caused by long-term cigarette smoking, which damages the elastic connective tissue of the alveoli. Bronchitis is inflammation of the bronchi, usually from pollution or cigarette smoke, producing a persistent cough, shortness of breath and sputum.

Pneumonia is inflammation of the lungs caused by a bacterial or viral infection, with symptoms including sputum production, nasal congestion, shortness of breath and sore throat; because it fills the alveoli with fluid or white blood cells, it directly reduces the surface area available for gas exchange and can become dangerous quickly if untreated, especially in the very young, the elderly, or people with weakened immunity. Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, mainly affects the lungs and bones and can lead to fluid collecting between the lungs and the chest wall. …