Chronic obstructive pulmonary disease (COPD) can usually be diagnosed using a medical history and lung function tests, such as spirometry. Your doctor will also conduct a physical examination and take a chest X-ray to rule out other conditions with similar symptoms, such as asthma. Some tests are done to rule out other diseases or conditions that may make COPD worse and its treatment more difficult.

Early detection of COPD is very important. The sooner you quit smoking and avoid other environmental factors that contribute to COPD, the better your chance of slowing damage to your airways and lungs.

Routine tests

• A history and physical exam provide important information needed to diagnose COPD and monitor its treatment.
• Lung function tests measure the amount of air in your lungs and the speed at which air moves in and out of the lungs and airways. They provide the essential information needed to diagnose, grade, treat, and monitor COPD. Spirometry is the most important of these tests.
• A chest X-ray helps ensure that there are no heart or lung problems (such as cancer) causing your symptoms.
• A complete blood count (CBC) can reveal information about how well oxygen is getting into the blood and about any possible infection.

Tests done as needed

• Arterial blood gases test measures the amount of oxygen, carbon dioxide, and acid in the blood. It is used in making the decision about using oxygen therapy.
• Oximetry measures the oxygen saturation in the blood. It can be useful in determining whether oxygen therapy is needed but provides less information than an arterial blood gases test.
• Electrocardiogram (ECG, EKG) or echocardiogram may diagnose certain heart problems that can cause shortness of breath.
• A sputum exam looks at coughed-up mucus (sputum) and is often used to determine whether you have a lung infection and can help to diagnose other diseases, such as asthma.
• Transfer factor for carbon monoxide (sometimes called a DLCO determination, or a lung-diffusing capacity for carbon monoxide) is a test to help determine whether your lungs have been damaged, and if so, the extent of the damage; the test is also used to assess the severity of your COPD.
• A bronchodilator response test helps to determine whether you need medications that open or relax the airways of the lungs and relieve shortness of breath (bronchodilators).

Tests rarely done

• A test to measure levels of alpha1-antitrypsin (AAT). AAT is a protein that helps protect the lungs from the damage caused by inflammation that can lead to emphysema and COPD.
• A computed tomography (CT) scan provides a detailed image of the lungs. It may be used to get a detailed look at lung damage caused by emphysema. It also may be used to diagnose other problems in the lungs, such as blood clots or possible tumors.

Regular checkups