What Causes the Symptoms of Cystic Fibrosis?
Normally, mucus is watery. It keeps the linings of certain organs moist and prevents them from drying out or getting infected. However, in cystic fibrosis, an abnormal gene, called the cystic fibrosis transmembrane conductance regulator (CFTR) gene, causes mucus to become thick and sticky. The thick, sticky mucus builds up in your lungs and blocks the airways. This makes it easy for bacteria to grow and leads to repeated serious lung infections. Over time, these infections can damage your lungs.
