what tests are done to diagnose copd
The best tests for diagnosing COPD and seeing how well it responds to treatment are pulmonary function tests. The gold-standard test for patients with respiratory symptoms is spirometry. Spirometry measures the volume and force of air as it is exhaled from the lungs. It measures airway obstruction, can identify COPD early, and the results are standardized so they are always consistent.
Questionnaires and short exercise tests are very useful for determining the severity of COPD. Test for alpha-1 antitrypsin deficiency. Physicians will typically test for the protective enzyme alpha-1 antitrypsin in COPD patients who are nonsmokers and who develop emphysema in their 30s.
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.
1 They also may show whether another condition, such as heart failure, is causing your symptoms. 2  An arterial blood gas test. 3  This blood test measures the oxygen level in your blood using a sample of blood taken from an artery. 4  The results from this test can show how severe your COPD is and whether you need oxygen therapy.
A bronchodilator challenge test may help distinguish between the two diseases. Some patients with COPD experience limited and temporary improvement in FEV1 30 - 45 minutes after inhaling medication from a metered dose inhaler. However, their airflow remains poor.