Chronic obstructive pulmonary disease - emphysema and chronic bronchitis

Emphysema and chronic bronchitis are both termed "chronic obstructive pulmonary disease" (COPD).The respiratory damage of COPD is considered to be irreversible. Generally it occurs as a result of smoking however exposure in the workplace to irritants such as chemicals and pollutants can also cause COPD.

Chronic bronchitis
Bronchitis means inflammation of the bronchi - the main airways that lead from the trachea (windpipe) into the lungs. If the bronchitis goes away once the infection responsible has cleared, the condition is termed acute bronchitis. The chronic form of bronchitis develops only after prolonged exposure to irritants, causing abnormalities to develop in the bronchial lining. The chronic inflammation causes excessive amounts of mucus - also known as phlegm or sputum - to be produced by the bronchi. This mucus then blocks the airways and air sacs (alveoli) reducing the amount of oxygen available to the lungs, causing breathlessness.

Emphysema
Emphysema often follows chronic bronchitis. If lung tissue is progressively damaged the lung loses its elasticity - its natural tendency to deflate or spring shut. The bronchial tubes, as a result, become swollen and inflamed, and their diameter may then become considerably reduced. Over time the air sacs (alveoli) are destroyed and replaced by scar tissue. Excessive amounts of mucous are characteristic of bronchitis, and this may further impair breathing. Emphysema can become terminal as all the energy available is spent trying to breathe through the damaged lungs.