Cystic fibrosis is a genetic disease that affects the way the body produces sweat, digestive fluids, and mucus. The main symptoms of CF are problems with the lungs, sweat glands, and digestive system. Today we will focus on the sweat glands.
When you have CF, extra salt escapes the body through your sweat. This can cause problems like nausea, stomach and muscle pain, exhaustion, and dehydration. Understanding the reasons for these problems can help you treat or avoid them.
How does CF affect sweat glands?
The main symptom of CF is thicker mucus caused by the cystic fibrosis transmembrane conductance regulator (CFTR). The CFTR changes the way salt moves in the body, which also affects the way the body sweats.
Your body keeps itself cool by releasing sweat. Salt helps carry the sweat to skin, and then the salt is reabsorbed in the body. But if you have CF, the salt isn’t reabsorbed. For a long time, parents have noticed that it tastes salty when you kiss a child with cystic fibrosis.
Salt is an important substance in the human body. It helps move fluids, digest food, and transmit information in the nervous system. Without salt, the body couldn’t work.
The fastest way a lack of salt affects the body is dehydration. When your body is running low on water, salt builds up. This extra salt tells your body that it’s thirsty and you need to drink some water. When the extra salt is escaping through the skin, you don’t realize you’re thirsty until it becomes a problem. Dehydration is a serious problem, but there are ways you can protect yourself.
Dealing with Salt Loss from Cystic Fibrosis
Being aware of your needs helps you avoid problems. Balancing the salt levels in your body can be done by drinking plenty of water and eating salty snacks. Staying hydrated is important for everyone, so always keep water on hand. Speak with your doctor or nutritionist about how much salt you need to have in your diet.
Cystic Fibrosis Sweat Test
One of the most useful tests for cystic fibrosis is the sweat test. After your baby goes through early tests, your doctor might want to perform a sweat test, a painless procedure that measures the level of salt in the baby’s sweat. Not every baby that has unusual results in the initial tests has CF, but it’s still important to perform the sweat test.
Your doctor will help you prepare your baby for testing. During the test, a gel is put on your baby’s arm or leg. The gel is covered with a patch with wires connected to it. The process is totally painless and simply encourages the skin to sweat. The sweat is collected to be tested. The entire procedure only lasts about 30 minutes. It will take a few days to get the results of the test.
When the test results arrive, your doctor will help you know how to proceed. A negative result means your baby doesn’t have CF. If the result is positive, that means your baby has too much salt in their sweat and probably has CF. If this happens, follow-up tests and treatment will be lined up. Sometimes the sweat test doesn’t provide enough information to know either way, so the test will need to be repeated.
Science of CF: CFTR: Function. Johns Hopkins Cystic Fibrosis Center. Accessed March 17, 2015.
Sweat gland. CFTR.info. Accessed March 17, 2015.
Davis P. Pathophysiology of cystic fibrosis with emphasis on salivary gland involvement. February, 1987. Accessed March 17, 2015.
What is the Sweat Test? Cystic Fibrosis Foundation. January 27, 2014. Accessed March 17, 2015.