Symptoms . CF causes the body to produce thick secretions that particularly affect the lungs and digestive tract. Symptoms of CF include: Troublesome cough Repeated chest infections Prolonged diarrhoea Poor weight gain However, these symptoms are not unique to CF. CF affects a number of organs but mostly affected are the lungs and pancreas. Lungs It is common for people with CF to encounter some difficulties with their lungs. A combination of physiotherapy and medication can help control lung infections and prevent lung damage. See the treatment/medication section of this site for further information. To avoid the risk of cross infection, people with CF need to ensure they do not come into close contact with others with CF.