Chronic Obstructive Pulmonary Disease

COPD is a relatively common condition. According to the American Lung Association, an estimated 16 million Americans have COPD and it is the fourth leading cause of death in the United States.

What Causes COPD?
In the United States, cigarette smoking is by far the most common cause of COPD. In fact, it is estimated that 90 percent of the diagnosed cases of COPD are related to cigarette smoke. Smoking depresses the lungs’ protective mechanisms and produces numerous other effects involved in the development of COPD.

COPD has also been linked to exposure to industrial agents. There are two main groups of agents that have been associated with the development of COPD. The first is certain chemicals -- such as ammonia, chlorine and acids like hydrofluoric acid -- that can produce changes in the airways if inhaled as a gas or vapor. The second group of agents is dusts produced within certain industries, such as coal mining.

In a small percentage of cases, a person may be predisposed to COPD due to a diagnosable hereditary condition.

How is COPD Diagnosed?
The diagnosis of COPD is based on patient history, symptoms, and physical signs, or it may become obvious through chest x-ray. However, to confirm a diagnosis of COPD, a breathing test must show that the individual cannot breathe out a sufficient amount of air in a certain period of time. This particular test measures air flow rate and is calculated by a machine called a spirometer.

Emphysema is a condition where the walls of the air sacs in the lung become weakened.  When this happens, the lungs cannot expand and contract normally. This causes a reduction in the airflow out of the lungs. Individuals with emphysema show symptoms at a relatively old age (often after age 60). The symptoms of this type of COPD are:

		Little or no cough or phlegm production
		Progressive shortness of breath on exertion

Chronic bronchitis is an inflammatory disease of the lung characterized by an increase in mucus in the airways. This excess mucus along with inflammation in the walls of the breathing tubes (bronchi) reduces the flow of air. Individuals with chronic bronchitis can develop symptoms at a relatively young age. The symptoms of this type of COPD are:

		Cough with phlegm production for at least 3 months for 2 or more consecutive years
		Episodes of shortness of breath on exertion

How does COPD Progress?
The progression of COPD depends mainly on how long a person has been exposed to the harmful substance and the amount of exposure. In general, COPD tends to get worse over time, particularly if exposure to the irritant continues. In many cases, if the exposure is stopped, for example, through smoking cessation or removal of the occupational irritant, the progression of the disease may be slowed or halted. However, in other cases, damage to the airways is so advanced that the progression of the disease may not be stopped, even if exposure no longer occurs.

How is COPD Treated?
There is no cure for COPD. However, treatment is available to reduce symptoms, slow progression, and minimize disability from the disease. COPD patients may benefit from certain classes of drugs, known as bronchodilators (which help open the airways) and corticosteroids (which decrease inflammation present in the airways).

In advanced cases, an individual may need supplemental oxygen throughout the day.  Some emphysema patients may have to undergo a surgical procedure that involves removal of large localized bullae (a group of damaged air sacs) in the lungs.

Prompt treatment of chest colds with the appropriate use of antibiotics can prevent episodes of COPD from worsening. In addition, COPD patients should receive annual vaccinations against influenza and a one-time pneumococcal vaccine (unless additional pneumococcal vaccines are recommended by your physician).

Pulmonary rehabilitation is done to improve the quality of life of individuals with COPD. These programs usually involve several components, including exercise to strengthen muscles. The goal of rehabilitation is to help people cope physically, psychologically and socially with COPD.

How Can COPD be Prevented?
Avoiding smoking is by far the most effective way to prevent COPD since the majority of COPD cases are caused by cigarettes. In cases where an industrial agent is suspected, stopping exposure to the toxic agent can also prevent the development of COPD.

For more information about COPD, the American Lung Association can be contacted at
1-800-LUNG-USA (1-800-586-4872) or on the Internet at www.lungusa.org