The evaluation of cystic fibrosis begins with a history and physical examination.

Physical findings in someone with cystic fibrosis may include:

• Clubbing of the fingers
• A broadening or thickening of the tips of the fingers that can be seen in some respiratory diseases as well as cancers.
• Enlargement of the spleen

Testing is necessary to make the diagnosis of cystic fibrosis.

Tests that may be used to evaluate cystic fibrosis include:

• Sweat chloride test
• Metal electrodes on the skin measure the concentration of sodium and chloride in the sweat.
• Can usually detect CF
• Genetic testing for CF
• Other tests are used to determine the presence and severity of complications of CF such as:
• 72-hour fecal fat determination, and testing the stools for trypsin and chymotrypsin
• Blood testing will generally show decreased serum albumin
• Blood testing for vitamins (vitamins A, D, E, and K)
• Glucose tolerance testing
• Skeletal bone x-rays
• Sputum culture (testing for pseudomonas bacteria)
• Chest x-ray
• Pulmonary function testing
• Echocardiogram