Cystic Fibrosis (here on out CF) is a genetic disease by way of a mutation that affects the ability of chloride to pass through cellular walls. This results in a lack of water balance in cells because it flows freely out of epithelial cells… which is a problem with mucus. Both sodium and chloride need to freely pass through to keep a balance. Here’s an illustration.
Lack of water balance results in thickened mucus that primarily manifests as a problem in CFers’ respiratory tract (including sinuses), pancreas, liver, skin, and digestive tract.
I’ll explain more soon. Still filling out site content.