Chronic obstructive pulmonary disease includes patients with emphysema and chronic bronchitis. Smoking is the leading cause.

This is the VOA Special English Health Report.

Chronic obstructive pulmonary disease, or C.O.P.D., affects more than two hundred million people around the world. The World Health Organization says at least five million people died from it in two thousand five. Ninety percent were in developing countries. 

		Smoking is the top cause of C.O.P.D.

In the United States, C.O.P.D. is the fourth leading cause of death. But even with these numbers, many people have never heard of it.

The Canadian Lung Association Web site explains that C.O.P.D. is the new name for emphysema and chronic bronchitis. These are the two most common forms of it, and many people with C.O.P.D. have both of them.

The result is progressive and incurable lung damage. The tubes that carry air in and out of the lungs become partly blocked. This makes it difficult to breathe and often produces a cough that will not go away.

People with C.O.P.D. often have swelling that causes the airways to narrow. And they often produce more mucus than normal. This oily substance protects the airways, but too much of it blocks them.

Smoking is the most common cause of C.O.P.D. Nonsmokers can get the disease from breathing other people's tobacco smoke.

Air pollution can also cause the disease. Miners and others who work around some kinds of dust and chemicals are at higher risk. And children who repeatedly suffer lung infections have a greater chance of developing the disease as adults. Genetics may also play a part.

Doctors can perform a quick breathing test with a machine called a spirometer that can help diagnose C.O.P.D. But experts say people are often not tested or treated correctly for chronic obstructive pulmonary disease.

Patients may not consider a continuous cough serious enough to seek medical attention. Or doctors may misdiagnose it as asthma or another infection.

Some of the early warning signs are a cough that will not go away and an increase in mucus production. Another sign is difficulty breathing after minor activity like walking up stairs.

There are ways to slow the progress of the disease. Doctors say the most important thing is to stop smoking. There are medicines that can reduce inflammation and open air passages. Also, exercise is often advised. If the disease is severe, a doctor may order oxygen treatment or even operations to remove damaged lung tissue.

And that's the VOA Special English Health Report, written by Caty Weaver. For transcripts and MP3 archives of our reports, go to voaspecialenglish.com. I'm Bob Doughty.