MODEL RELEASED. Cystic fibrosis (CF) patient using a nebuliser; inhaling its fine spray assists in loosening mucus secretions in the lungs. Subsequent chest massage techniques are used to encourage patients to expectorate & clear their lungs. Cystic fibrosis is an inherited disorder that results in an overproduction of thick mucus, which obstructs the bronchi, intestinal glands & pancreas. Severe respiratory infections are a common complication. Advances in molecular genetics have resulted in the identification of the CF gene; this is applied in diagnostic tests & in counselling carriers.