Cystic Fibrosis - Exams and Tests

Most people who have cystic fibrosis have signs of it when they are children. Tests to diagnose cystic fibrosis can be done at any time—before pregnancy, during pregnancy, right after birth, in childhood, or in adulthood.

Diagnosis

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:

• Your child has early symptoms. These may include diarrhea that does not go away; large, greasy or very smelly stools; constipation; not wanting to eat; or losing weight. To learn more, see Symptoms.

• A brother or sister who has cystic fibrosis.
• A positive newborn screening test.

Also, there must be at least one of the following:

• 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.
• A positive genetic test for the genetic defect that is known to cause cystic fibrosis. This testing can be done using blood or a sample from the mother's womb before birth (chorionic villus sampling or amniocentesis).
• 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

Article Referenced from WebMD