COPD (Chronic Obstructive Pulmonary Disease)

Definition
Chronic obstructive pulmonary disease (COPD) is a group of lung diseases that cause swelling of the airways. Emphysema and chronic bronchitis are the most common forms of COPD.

Emphysema is a lung disease that involves damage to the air sacs (alveoli) in the lungs. The air sacs become dilated and are unable to deflate completely with breathing. This renders them incapable of filling with fresh air and limits their ability to move oxygen into the bloodstream, thus decreasing the amount of oxygen that gets to the body tissues.

Chronic Bronchitis is an inflammation of the main airways (bronchi) that persists for a long period of time or recurs repeatedly. It is characterized by a cough that is productive of mucus for 3 months or more in at least 2 consecutive years, without the presence of any other disease that could account for this symptom.

Causes, incidence and risk factors
The leading cause of COPD is smoking. Prolonged tobacco use causes lung inflammation and destroys the air sacs in the lungs. Other risk factors for COPD are exposure to second-hand smoke, male gender and working or living in a polluted environment.

Symptoms

• Shortness of breath (dyspnea) persisting for months to years
• Wheezing
• Decreased exercise tolerance
• Cough with or without phlegm

Tests

• A chest X-ray can show an over-expanded lung (hyperinflation), and a chest CT scan may show emphysema.
• A sample of blood taken from an artery (arterial blood gas/ABG) may show low levels of oxygen (hypoxemia) and high level of carbon dioxide.
• Pulmonary function tests show decreased airflow rates while exhaling, and air-trapping.