A Closer Look at Tests to Confirm Sarcoidosis
Lung Function Test
One lung function test uses a spirometer -- a device that measures how much and how fast you can blow air out of your lungs after taking a deep breath. If there is a lot of inflammation and/or scarring in your lungs, you will not be able to move normal amounts of air in and out.
Another test measures how much air your lungs can hold. Sarcoidosis can cause your lungs to shrink, and they will not be able to hold as much air as healthy lungs.
An electrocardiogram (EKG) will help show if your heart is affected by sarcoidosis.
In this test, a small clip attached to your fingertip can show how well your heart and lungs are moving oxygen into your blood.
Arterial Blood Gas Test
This test is more accurate than pulse oximetry for checking the level of oxygen in your bloodstream. Blood is taken from an artery (usually in your wrist). It is then analyzed for its oxygen and carbon dioxide levels.
In this procedure, your doctor inserts a long, narrow, flexible tube with a light on the end through your nose or mouth into your lungs to look at your airways. This tube is called a bronchoscope. You most likely would have this procedure as an outpatient in a hospital under local anesthesia.
During a bronchoscopy, your doctor may inject a small amount of saltwater (saline) through the bronchoscope into your lungs. This procedure is called a bronchoalveolar lavage (BAL). The fluid washes the lungs and helps bring up cells and other material from the air sacs deep in your lungs, where the inflammation usually starts to develop. The cells and fluid are then examined for signs of inflammation.