CF causes extremely salty skin.
A damaged salt chloride channel causes an individual with CF to emit high levels of salt. In other words, the more they sweat, the more they lose salt – increasing their risk of dehydration. Another problem with salty mucus is that it makes it harder for the body’s white blood cells to kill the germs that make their way into the respiratory system. Therefore, when an individual with CF gets a respiratory infection, the body tries to fight it off by producing more mucus – which essentially makes the problem worse.
To this day, the diagnostic test for CF is called a “sweat test” because it measures the salt chloride levels in the sweat.