How is COPD Diagnosed?
A spirometry test measures how well your lungs are working. It’s a simple and easy test that can help diagnose COPD.
A person may have chronic obstructive pulmonary disease (COPD) but not notice symptoms until it is in the moderate stage. This is why it’s important to ask your doctor about taking a spirometry test if you are a current or former smoker, have been exposed to harmful lung irritants for a long period of time, or have a history of COPD in your family, such as Alpha-1 Antitrypsin Deficiency related COPD.
Who should get tested for COPD?
If you have any of these symptoms, you may have COPD.
Anyone with the following should get tested:
- long-term exposure to air pollutants (including pollution and second-hand smoke)
- chronic coughing with or without sputum
- shortness of breath
- An ability to keep up with people of your own age
How can I get tested?
Start by taking our 5-question Risk Screener, then talk to your doctor about taking a spirometry test. Early screening can identify COPD before major loss of lung function occurs.
What is a spirometry test?
Spirometry is a simple, non-invasive test that is used to diagnose COPD. When you take the test, you will be asked to blow all the air out of your lungs into a mouthpiece connected to a machine known as a spirometer.
The machine will calculate two numbers: the amount of air you blow out in the first second, and the amount of air you can completely blow out.
These numbers are represented as FEV1 and FVC. FEV1 stands for the forced expiratory volume in the first second—the amount of air you forcefully exhaled in the first second of blowing. FVC stands for forced vital capacity—the amount of air that you exhaled in one entire breath.
A spirometry test can also show your doctor how severe your COPD may be. There are several stages of COPD. The extent of your COPD is classified into 4 different stages that are defined by your symptoms and the results of your spirometry test. The stages do not determine how long you can expect to live, or in many cases how drastically your symptoms are affecting your quality of life. The stages are designed to help your physician in prescribing your treatment protocol. In order to determine what stage you are in, your pulmonologist, based on your symptoms, may administer one or more pulmonary tests.
Most people are able to blow about 80% of their lung volume in the first one second. People with COPD have an FEV1/FVC ratio less than 70%. The FEV1 percentage predicted indicates how severe the airflow is obstructed (blocked or narrowed) in comparison with people of your age, gender, and height.
FEV1 less than 80% of predicted is considered moderate COPD, and less than 50% of predicted is severe. People with asthma will have a low FEV1/FEV ratio when they are having an attack, and then will return to normal or almost normal after using fast-acting medications.
Your doctor may order additional tests to see if your symptoms are caused by lung disorders other than COPD.
Your doctor may also order a chest x-ray or a chest CT (high resolution computed tomography), which shows your lungs in much greater detail, to see if your symptoms are brought on by other problems instead of COPD.
Why is it important to get tested?
Leaving symptoms misdiagnosed, untreated, or undertreated may cause them to worsen faster than if they were treated with proper medication and therapy. Many adults are incorrectly diagnosed with asthma. Providing a proper diagnosis means individuals will receive the right treatments and follow-up monitoring. There is no cure yet for COPD but treatments are available to help individuals live better.