Along with a complete health history and physical exam, your doctor may do pulmonary function tests. These tests help measure the lungs' ability to exchange oxygen and carbon dioxide. The tests are often done with special machines into which you breathe. They may include:
Spirometry
A spirometer is a device used to check lung function. Spirometry is one of the simplest, most common tests. It may be used to:
- Determine the severity of a lung disease
- Find out if the lung disease is restrictive (less air will get into your lungs) or obstructive (less air will get out of your lungs)
- Look for lung disease
- Monitor how well treatment is working
Peak flow monitoring
This device measures how fast you can blow air out of your lungs. Cough, inflammation, and mucus buildup can cause the large airways in the lungs to slowly narrow. This slows the speed of air leaving the lungs. This measurement is very important in seeing how well or how poorly the disease is being controlled.
Blood tests
These are done to check the amount of carbon dioxide and oxygen in the blood. A blood test may be done to check eosinophil counts and vitamin D levels, and to monitor your hematocrit and hemoglobin levels for anemia.
Chest X-ray
This test takes pictures of internal tissues, bones, and organs. A chest X-ray is not recommended to diagnose COPD, but it can help identify other conditions.
CT scan
This test uses a combination of X-rays and computer technology to make images of the body. A CT scan can show details, such as the width of airways in the lungs and the thickness of airway walls.
Mucus (sputum) culture
This test is done on the material that is coughed up from the lungs and into the mouth. A sputum culture is often used to see if an infection is present. It may also be done to check eosinophil levels. It generally takes 2 days to get the results.