People with CF can have a variety of symptoms including:
- Very salty-tasting skin
- Persistent coughing (at times with phlegm)
- Frequent lung infections
- Shortness of breath
- Poor growth/weight gain in spite of a good appetite
- Frequent greasy bulky stools
- Difficulty in bowel movements
- Sinus issues
Most people are diagnosed with CF at birth or before age two. A doctor who sees signs and symptoms will order either a sweat test or a genetic test to confirm the diagnosis.
A sweat test is the most common test used to diagnose cystic fibrosis. A small electrode is placed on the skin (usually on the arm) to stimulate the sweat glands. Sweat is then collected and the amount of chloride, a component of salt in the sweat, is measured.
In a genetic test, a blood sample or cells from the inside of the cheek is taken and sent to a laboratory to see if any of the various mutations of the CF gene are found. A genetic test is often used if the results from a sweat test are unclear.