What’s the difference between awareness and understanding? The answer could save your life.

COPD, chronic obstructive pulmonary disease, is a serious lung disease that over time makes it hard to breathe. It is the fourth-leading cause of death in the United States. A recent national survey found that while awareness of COPD is growing, understanding of the disease, its risk factors and symptoms remains low.

The National Heart, Lung, and Blood Institute of the National Institutes of Health analyzed results from the annual HealthStyles survey of American public health attitudes.

The NHLBI found that 64 percent of respondents have heard of COPD (this up from 49 percent in a similar survey conducted in 2004). However, most respondents could not name smoking as a key risk factor for COPD, and many did not recognize chronic cough or “smoker's cough” as a common symptom of the disease.

“While we applaud the millions of Americans who have heeded the public health community's call to quit smoking, it's important that both current and former smokers know that they remain at risk for COPD,” said James P. Kiley, Ph.D., of the NHLBI.

COPD kills more than 120,000 Americans each year. The NHLBI estimates that half of the 24 million living with COPD do not know they have the disease. With COPD, the airways of the lungs are narrowed, making it hard to get air out and causing an “out of breath” feeling.

Other symptoms include frequent coughing, excess mucus and wheezing. Most people with COPD are over 40 with a history of smoking or long-term exposure to fumes or pollutants in the environment.

If you think you might be at risk for COPD, the NHLBI recommends that you ask your doctor about a simple breathing test called spirometry. The lung function test involves breathing out as hard and fast as you can into a tube connected to a machine, and it can be done right in the doctor's office.

If you find out you have COPD, there is hope. Many treatments are available to reduce symptoms, improve breathing and help you get back to doing more of what you used to do.

You can find out more at www.LearnAboutCOPD.org, part of the NHLBI's COPD Learn More Breathe Better education and awareness campaign.