Cystic fibrosis can lower the normal salt levels in the body, which can lead to a variety of short- and long-term problems.

Sweat glands cool the body by releasing perspiration (sweat) from the lower layers of the skin onto the surface. Sodium and chloride (salt) help carry water to the skin's surface and are then reabsorbed into the body. As the water evaporates, heat is carried away, and the body cools.

In people who have cystic fibrosis, the salt travels to the skin's surface with the water and is not reabsorbed. Because of this, the skin of a child who has cystic fibrosis is abnormally salty. Parents may notice salty-tasting skin when they kiss the child.

People who have cystic fibrosis can become quickly depleted of salts and cannot cool off, especially when the weather is hot, when they exercise strenuously, or when they have a fever. Salt levels in the body become depleted, leading to fatigue, weakness, fever, muscle cramps, stomach pain, vomiting, dehydration, and heatstroke. To avoid these conditions, people who have cystic fibrosis need to keep well hydrated and maintain healthy salt levels in the body.