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Lung Disease & Respiratory Health Center

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Nasal Potential Difference Test for Cystic Fibrosis - Topic Overview

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

Understanding Sarcoidosis -- the Basics

Sarcoidosis is a chronic disease that affects multiple systems in the body, from the eyes to the lungs to the brain. It is characterized by the buildup of immune system cells in organs that form small clusters called granulomas, a type of inflammation of the involved tissues. Sarcoidosis is found throughout the world. While the disease can affect anybody, young women of African descent and people of Scandinavian, German, Irish, or Puerto Rican origin are more prone to sarcoidosis. It occurs...

Read the Understanding Sarcoidosis -- the Basics article > >

This test is not used very often because it can be difficult to do and because it is not available in many places.

WebMD Medical Reference from Healthwise

Last Updated: September 09, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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