Cystic Fibrosis - Exams and Tests
Tests can help find out if a person has cystic fibrosis or has the changed gene that can be passed on to a child. Adults may want to get tested during a pregnancy or when they are planning for a pregnancy. People can be tested at any age to see if they have cystic fibrosis.
A medical history and a physical exam are often the first steps in diagnosing cystic fibrosis, followed by screening or lab tests.
The diagnosis of cystic fibrosis requires one of the following:
Also, there must be at least one of the following:
- A genetic test showing that a person inherited one or two defective cystic fibrosis transmembrane regulator (CFTR) genes. This testing can be done using blood or a sample from the mother's womb before birth (chorionic villus sampling or amniocentesis).
- Two positive sweat tests on different dates. Sweat tests measure the level of salt in sweat. People with cystic fibrosis have more than the normal amount of salt in their sweat. If a genetic test detects two defective CFTR genes, then just one sweat test result may be all that is needed to confirm a diagnosis.
- An abnormal nasal potential difference test. This test uses electrodes on the lining of the nose to see how well salts flow into and out of cells.
Monitoring cystic fibrosis
Certain tests can help your doctor monitor your child's cystic fibrosis. These tests include: