A Pulmonary Function test is a breathing test that measures how well your lungs are working. There are many reasons why your physician may need to have you perform a Pulmonary Function test. The most common of these are:
- shortness of breath
You may need to have Pulmonary Function tests performed regularly if you have been diagnosed with a lung disease like:
- pulmonary fibrosis
You may also need to have Pulmonary Function tests performed in order to obtain a baseline for:
- radiation therapy
Some tests can be performed in your physician’s office but many will need to be performed in a Pulmonary Function Lab by trained technicians. Your physician will order the tests that he believes will be most helpful in diagnosing or monitoring your condition.
In order to perform any Pulmonary Function Test you will need to breathe in very specific ways and at very specific times. The technician performing your tests should be able to explain how and when you are supposed to breathe. The ways in which you will need to breathe may often seem peculiar but there are good reasons for every breathing maneuver you will be asked to perform.
Most people are able to perform these breathing maneuvers either right away or with some practice. Occasionally however, some individuals have difficulty performing these tests. There are several relatively common reasons that this can happen.
Latest Q & A:
I’m coughing mucus sometime with blood
for a year hrct [High Resolution Cat Scan] normal bronchoscopy normal Spirometry jan 17 Fvc 5.24 112% Fev1 4.80 105% Dlco 94% Spirometry aug 17 Fvc 4.80 98% Fev1 4.00 97% Dlco 104% I don’t have a clear diagnostic my dr belive i may have a prolonged infection
Response: Although both spirometry tests are probably within normal limits you had a significant decrease in FEV1 between January and August (-17%). This isn’t as apparent as it should be since the predicted FEV1 (and FVC) are different for the two tests. In January the predicted FEV1 was somewhere around 4.57 L and in August it was around 4.12 L so you either had your tests at two different places or they changed reference equations in between.
A decrease in FEV1 like that could be a concern but some people are normally variable, or it could be a difference between testing systems or it actually could indicate a trend. You won’t know for sure until you are tested again. At the moment however, your August results, which includes your DLCO, are within normal limits so I wouldn’t be overly concerned about it at this time.
A chronic cough is, unfortunately, a non-specific symptom. It can be due to a wide variety of lung disorders but just as often it is due to allergies or environmental causes. Frequent or violent coughing can also cause hemorrhaging of the blood vessels in the airways so the blood in your sputum may be due to the cough and not to an underlying lung disorder.
It is possible you have a lung infection but these are often difficult to diagnose since there are a wide variety of bacterial, fungal and viral causes. I’m not up to date on diagnosing lung infections (not my area of expertise anyway) but having your sputum cultured for organisms used to be a relatively common practice. It would be best if you talked to your physician about this.