What Is a Sweat Test for Cystic Fibrosis?

Q:
What is a sweat test for cystic fibrosis?

A:
Cystic fibrosis is an inherited disorder that causes breathing problems, lung disease, nutrition problems, and problems in digestive system.

Since salty skin is one of the primary symptoms of cystic fibrosis, a sweat test is a common way to diagnose cystic fibrosis. The test is painless and can be done very quickly, and its results are highly accurate.

In general, a sweat test will test the concentration of chloride in a sweat sample. And it can diagnose cystic fibrosis according to the diagnostic ranges.

For newborn babies under six months, the diagnostic ranges are:

  • Negative (cystic fibrosis is ruled out): less than 30 mmol/L
  • Borderline (inconclusive): between 30 and 59 mmol/L
  • Positive (cystic fibrosis is confirmed): 60 mmol/L or greater

For other children and adults, the diagnostic ranges are:

  • Negative (cystic fibrosis is ruled out): less than 40 mmol/L
  • Borderline (inconclusive): between 40 and 59 mmol/L
  • Positive (cystic fibrosis is confirmed): 60 mmol/L or greater

Keywords: sweat test cystic fibrosis

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.