Chronic Obstructive Pulmonary Disease (COPD)
-Brief Overview of COPD-
Chronic obstructive pulmonary disease is a group of diseases that includes emphysema, chronic bronchitis, asthma, and a combination of the three. Most people with COPD have a combination of these with lung irritation. The damage to the airways and broken-down alveoli is healed by scar tissue. This scarring becomes structure and can progress, but cannot return to oxygen-exchanging normal lung tissue.
-Effects of COPD-
In emphysema the alveoli, or tiny air sacs in the lungs, no longer are elastic and behave more like paper bags than rubber balloons. A paper bag does not stretch like a balloon and no longer can empty simply by relaxing. In addition to losing their elasticity, some of the air sacs break down and there are fewer sacs to be filled. Inadequate available alveoli and capillaries to exchange oxygen cause the individual to be short of breath. Another reason for shortness of breath is that the air sacs do not empty completely and stale air with a higher proportion of carbon dioxide stays in the lungs. The fresh air cannot get in. The smaller airways become weaker and collapse when an attempt is made to force air out too quickly or too forcibly. This traps more stale air in the alveoli.
Thus in emphysema, the major problem is decreased available functioning air cells with which to exchange oxygen and carbon dioxide. Activity requires more available oxygen. The person with emphysema becomes fatigued and out of breath easily. The causes of emphysema are unknown, but major contributing factors are:
With asthma, the irritation causes the airways to become narrow and to close temporarily. This is called a bronchospasm. Wheezing is heard as air tries to pass through narrow and clogged airways. With bronchospasm, the problems are the same as for chronic bronchitis. The difference is that with asthma, allergies to certain substances or emotional crises trigger an attack, and the airways stay narrow temporarily.
In chronic bronchitis, the branches or bronchioles become inflamed or remain narrow because of constant irritation.
Narrow airways make it more difficult to get air out of the lungs. Chronic irritation causes more mucus production and more coughing, which further irritates the bronchioles. With the excess coughing, the diaphragm flattens, replacing the dome shape. When flattened, the diaphragm does not function as an effective bellows for its job of expanding the chest capacity for air exchange. Major causes of bronchitis also are cigarette smoking, air pollution, and repeated chest colds.
-Links to Other Informative Sites-