Sweat Test

Last Friday was the start of all my tests, since my cystic fibrosis diagnosis back in August. My genetic markers are a little different than most. Delta F508 (which is the most common cystic fibrosis marker), and 3737c>t. There are currently only 2 other people in the world diagnosed with this particular marker. My doctor wanted me to get a bunch of tests completed before she decides how to treat me. So far I have completed a sputum culture (which came up part positive for micro bacterium) and a sweat test. Over the next two weeks I will be getting a glucose tolerance test, routine blood labs, a stool sample, and CT of the chest. 

What is a sweat test? 

A sweat test measures the amount of sodium chloride that is excreted in the sweat. Sodium chloride is elevated in patients with cystic fibrosis.

What is a sweat test used for?

A sweat test is used to help diagnose cystic fibrosis especially if the genetic markers are unknown. It is the standard test on how to diagnose cystic fibrosis. It can be tested on anyone with symptoms of cystic fibrosis, but most of the time it is done on infants with a positive newborn screen. 

How to prepare?

I was told to drink a lot of water or juice the day before the test. You don't want to drink anything that has a lot of sodium (Gatorade or soda) because they will be testing for sodium in the sweat. This is not a fasting test, so you can schedule it anytime during the day. 

I was a little nervous about the test, because I had no idea what to expect. The testing took about an hour total. First they clean two areas on your arm, and strap these gel like pieces to each place. They leave them on for about 10 min, and then wipe the area clean once they come off. They then strap a collection tubing (the blue dye is to mark how much sweat is collecting in the tubes) in the same place and leave them strapped to your arm for about 15 min. Afterwards they pull out the tubing and drains the sweat into two tiny tubes. The equipment looks much scarier than it actually is. During the test there is some burning but it is not painful. It did burn my skin a little but after a few hours the marks were gone.  

The most difficult thing about getting tests and going to doctors appointments is the time that it takes out of your day. This particular test only took about an hour, but combined with registration and driving the total time was about 2.5 hours. I know this is just the start of testing, and doctors appointments so I need to find the positives and look forward to learning more about the disease and the tests that come along with it.