Nasal Potential Difference Test for Cystic Fibrosis
The nasal potential difference test (nasal PD test) measures how well
salts (sodium and chloride) flow across the mucous membranes in the nose. This
type of test can be helpful when the results of a sweat test or a genetic test
are not clear.
In this test, electrodes are placed inside the nose and liquids are
run through the nose. There is also a needle placed in the forearm that
connects to a machine. Because this test can be uncomfortable, your child may
need medicine to help him or her relax before having the test.
Recommended Related to Lung Disease/Respiratory Problems
If your doctor suspects sarcoidosis, he or she will do the following:
Review your medical history
Perform a physical exam
Order chest X-rays and blood tests that may aid in the diagnosis
In 90% of people with sarcoidosis, chest X-rays show abnormalities. Many patients also have a low white blood cell count. Your doctor may also order pulmonary-function tests, which measure how well your lungs are working. Tissue biopsies (tests on small tissue samples) from your lungs may be done to...