A sweat test measures the amount of chloride in sweat . Chloride is part of the salt that's found in sweat. The test can diagnose cystic fibrosis (CF) because people with CF have higher levels of chloride in their sweat.
CF is an inherited disease that can affect people of all ages. To have cystic fibrosis, you must inherit a changed CFTR gene from both your parents. (Changes in genes are also called variants or mutations.) If you inherit one changed gene, you won't have the disease, but you will be a carrier. Being a carrier means that if you have children with someone who also has changes in one or both of their CFTR genes, your children could inherit two changed genes and have CF.
The disease affects the parts of your body that make mucus and sweat. Normally, mucus is slippery and protects the linings of your airways, digestive tract, and other organs and tissues. With CF, mucus becomes thick and sticky. It can build-up in your organs and cause damage.
CF commonly affects the lungs. Thick mucus may make it hard to breathe and can lead to frequent lung infections and damage. Another common problem from CF is malnutrition because the disease may reduce your body's ability to absorb nutrients from food.
Other names: sweat chloride test, cystic fibrosis sweat test, sweat electrolytes