Salt and sweat

Find out how cystic fibrosis (CF) affects the movement of salt and water in and out of cells, and how this can lead to salty sweat and skin for people with the condition.

As CF is caused by a faulty gene that controls the movement of chloride and water into and out of cells, people with CF often sweat more than people without the condition, and this sweat contains high levels of chloride, which can crystallise into salt visibly on the skin. Measuring the amount of chloride in sweat is often used during the process of diagnosing CF, through a procedure called the ‘sweat test’.

Why do people with CF have salty skin?

In people with CF there is a problem in the transport of chloride across cell membranes. This causes thicker, stickier mucus in the lungs and digestive system, but also results in higher levels of chloride (as salt) in sweat compared with those who do not have cystic fibrosis. Some parents who have newborn babies with CF have reported noticing that their skin tastes salty when they kiss them. Find out more about the science behind what causes cystic fibrosis.

How is salty skin treated?

Salty skin is not a problem in itself. However, as people with CF can lose more salt in their sweat it is often advised that they increase the salt intake in their daily diet, especially when doing exercise or in hot weather where they may sweat more. You can find out more about salt in the CF diet in our nutrition factsheet on the topic.

Do people with CF sweat more?

Although excessive sweating in itself is not known to be directly related to CF, anecdotally many people with the condition report having excessive sweating. For tips on dealing with excessive sweating, take a look at our body image booklet.