The sweat test is done to rule out cystic fibrosis. It also may be used to test people with a family history of cystic fibrosis and for anyone with symptoms of cystic fibrosis.

Pulmonary function testing is a broad range of tests that measure how well the lungs take in and exhale air and how well they transfer oxygen into the blood.

Blood or cheek scraping cells can be tested for mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Other blood tests can assess infection, and involvement of certain organs.

These are diagnostic tests which use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film. This can help determine fluid build up in the lungs.

Sputum cultures are diagnostic tests performed on the material that is coughed up from the lungs and into the mouth to determine if an infection is present.

These help to measure stool fat absorption.