COPD is the acronym for Chronic Obstructive Pulmonary Disease. It is the collective term for a couple of disorders that are characterized by persistent blockage of airflow into the lungs making breathing more difficult. These two disorders, which often co-exist, are chronic bronchitis and emphysema.

COPD is indeed one of the grave illnesses that are brought about by smoking. In fact, smoking is the cause of more than 80 percent of all COPD cases, although only 15-20 percent of smokers develop the disease.

Smokers are 12-13 times as likely to die from COPD as people who have never smoked.

The other less common causes of COPD are exposure to polluted air and second-hand smoke, childhood respiratory infections and heredity.

The air a person inhales passes through a system of tubes — nose, pharynx, larynx (voice box), trachea (windpipe) and bronchial tubes — before it reaches the air sacs (alveoli) in the lungs from where oxygen from the inhaled air goes into the blood.

Chronic bronchitis refers to unrelenting inflammation of the lining of the bronchial tubes. This inflammation causes excessive mucus production and thickening of the linings of the bronchial tubes resulting in less air being able to flow from and into the air sacs (alveoli). Chronic bronchitis is characterized by a constant cough that is often productive of thick phlegm. Typically, a person with chronic bronchitis has productive cough most days of the month at least three months a year.

Inflamed bronchial tubes are ideal sites for bacterial infection which aggravates the airflow problem. Eventually, the constant inflammation and frequent infections lead to scarring of the lining of the bronchial tubes.

Emphysema, on the other hand, refers to the irreversible destruction and weakening of the walls of the alveoli or air sacs. As air sacs are destroyed, the lungs are able to transfer less and less oxygen to the bloodstream, causing shortness of breath.

As the bronchial tubes get scarred and the air sacs get destroyed, the lungs lose their elasticity and it becomes increasingly difficult to keep the airways open. Consequently, air gets trapped in the lungs and exhalation becomes difficult.

COPD does not occur suddenly. It develops over many years. No wonder then that the initial symptoms of the disease, mild cough productive of clear sputum, usually do not appear before 45 years of age. Usually, at the onset of COPD, shortness of breath is just intermittent and minimal, but if the disease progresses, the quality of life of the patient slowly deteriorates, the shortness of breath becomes increasingly worse and the sputum changes in color from clear to yellow or green.

The damage to the bronchial tubes and air sacs that are caused by COPD are irreversible, but progress of the disease can be slowed down, if not totally arrested, by such measures as stoppage of smoking, avoidance of second-hand smoke, air pollution and other air-borne irritants.

Since the changes caused by COPD are irreversible, there is no cure for the disease. The aim of treatment in COPD is to relieve the symptoms and prevent the complications and progression of the disease.

Bronchodilators (i.e., drugs that widen the lumen of the bronchial tubes), in the form of aerosol sprays of oral preparations are the mainstays in the symptomatic management of COPD. Other drugs that are often employed include antibiotics (when infection is present) and corticosteroids (inhaled or oral preparations). The latter however, have serious adverse effects if taken over prolonged periods of time.

Pneumonia and influenza vaccines are also advisable for COPD patients, because these illnesses aggravate the damage caused by COPD.

Ultimately, COPD patients may need to be given oxygen therapy.

People with severe COPD usually die from respiratory failure, pneumonia, collapse of the lungs due to pneumothorax, or heart abnormalities or failure.