Cystic fibrosis (CF) is an inherited disorder that causes severe damage to the lungs, digestive system and other organs in the body. Cystic fibrosis signs and symptoms vary, depending on the severity of the disease. Even in the same person, symptoms may worsen or improve as time passes. Some people may not experience symptoms until their teenage years or adulthood. People who are not diagnosed until adulthood usually have milder disease and are more likely to have atypical symptoms, such as recurring bouts of an inflamed pancreas (pancreatitis), infertility and recurring pneumonia. Cystic fibrosis (CF) is a genetic disorder, which means you get if from your parents at birth. It affects the way your body makes mucus, a substance that helps your organs and systems work. Mucus should be thin and slippery, but when you have CF, it becomes thick and glue-like. This blocks tubes and ducts throughout your body. Cystic fibrosis is caused by a change, or mutation, in a gene called CFTR (cystic fibrosis trans membrane conductance regulator). This gene controls the flow of salt and fluids in and out of your cells. If the CFTR gene doesn’t work the way it should, a sticky mucus builds up in your body.