Your doctor will diagnose COPD based on your signs and symptoms, your medical and family histories, and test results.
Your doctor may ask whether you smoke or have had contact with lung irritants, such as secondhand smoke, air pollution, chemical fumes, or dust.
If you have an ongoing cough, let your doctor know how long you've had it, how much you cough, and how much mucus comes up when you cough. Also, let your doctor know whether you have a family history of COPD.
Your doctor will examine you and use a stethoscope to listen for wheezing or other abnormal chest sounds. He or she also may recommend one or more tests to diagnose COPD.
Lung function tests measure how much air you can breathe in and out, how fast you can breathe air out, and how well your lungs deliver oxygen to your blood.
The main test for COPD is spirometry (spi-ROM-eh-tre). Other lung function tests, such as a lung diffusion capacity test, also might be used. (For more information, go to the Health Topics Lung Function Tests article.)
During this painless test, a technician will ask you to take a deep breath in. Then, you'll blow as hard as you can into a tube connected to a small machine. The machine is called a spirometer.
The machine measures how much air you breathe out. It also measures how fast you can blow air out.

The image shows how spirometry is done. The patient takes a deep breath and then blows hard into a tube connected to a spirometer. The spirometer measures the amount of air breathed out. It also measures how fast the air is blown out.
Your doctor may have you inhale medicine that helps open your airways and then blow into the tube again. He or she can then compare your test results before and after taking the medicine.
Spirometry can detect COPD before symptoms develop. Your doctor also might use the test results to find out how severe your COPD is and to help set your treatment goals.
The test results also may help find out whether another condition, such as asthma or heart failure, is causing your symptoms.
Your doctor may recommend other tests, such as:
The NHLBI "Grand Opportunity" Exome Sequencing Project
Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway for COPD, visit www.clinicaltrials.gov.
November 21, 2012
CDC and NIH survey provides first report of state-level COPD prevalence
The age-adjusted prevalence of chronic obstructive pulmonary disease (COPD) varies considerably within the United States, from less than 4 percent of the population in Washington and Minnesota to more than 9 percent in Alabama and Kentucky. These state-level rates are among the COPD data available for the first time as part of the newly released 2011 Behavioral Risk Factor Surveillance System (BRFSS) survey.

If you have COPD or think you might be at risk, you can take steps to make breathing easier and live a longer and more active life. Get a simple breathing test and talk with your doctor or health care provider about treatment options.
The NHLBI developed the national COPD Learn More Breathe Better® campaign to increase awareness of COPD. The campaign aims to help people with COPD and those at risk get diagnosed early, understand their treatment options, and live better with the disease.
Learn more about key campaign events, activities, and resources.
The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.