If you are referring to cystic fibrosis
, the standard diagnostic test is to conduct 2 back-to-back sweat chloride
These tests measure the amount of sodium and chloride in the sweat content; levels of 60 milliequivalents per liter or above are considered diagnostic. The disease can also be diagnosed by running
a genetic test, but this is more expensive.
Answer assisted by David Escobar, Medical Student