It is a genetic condition, caused by a faulty gene that affects the movement of salt and water in and out of cells. This, along with recurrent infections, can result in a build-up of thick, sticky mucus in the body's tubes and passageways – particularly the lungs and digestive system. This is not a contagious disease.
There's no cure for CF, but a range of treatments can help control, prevent or reduce complications, and make the condition easier to live with.