How is CF diagnosed?
A. A doctor who sees the symptoms or is suspicious of Cystic fibrosis 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 collected and the amount of chloride, a component of salt in the sweat, is measured. The best place to receive a reliable sweat test is at a Cystic Fibrosis Foundation-accredited care center.
Most people are diagnosed with CF at birth through newborn screening, or before the age of 2. A doctor who sees the symptoms of CF will order a sweat test or a genetic test to confirm the diagnosis. A sweat test is the most common test used to diagnose cystic fibrosis and is considered the diagnostic “gold standard.” 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. A high level of chloride means that the person has cystic fibrosis. For children who are less than six months old: • Chloride levels at or above 60 mmol/L (a measure of concentration) means the child has CF. • Chloride levels between 30 and 59 mmol/L are considered borderline and need to be examined on a case-by-case basis. • Chloride levels below 30 mmol/L are considered negative for CF. For people over the age of six months: • Chloride levels at or above 60 mmol/L means the person ha
