There are many ways in which cancer can cause fatigue. The growth of a tumor, in general, can be taxing for your body. Other symptoms of cancer such as shortness of breath, anemia, pain, or a decreased level of oxygen in your blood (hypoxia) can cause fatigue.
A pulmonary function test may take 30 to 60 minutes to complete. This will vary according to the amount of trials necessary for you to get repeatable test results.
A pulmonary function test (PFT) evaluates how well your lungs work. PFTs measure the amount of air in your lungs, how well the lungs move air in and out, and possibly how medications affect the lungs.he complete pulmonary function test (or complete PFT) requires you to perform the spirometry, lung volume, and DLCO. The therapist may perform tests that measure how your lungs respond to outside factors such as medications, allergens or exercise.