Coughing, the most noticeable symptom, is often accompanied by gagging, vomiting, and disturbed sleep. As the disease progresses, the chest becomes barrel-shaped, and insufficient oxygen may make the fingers clubbed and the skin bluish. Polyps may form in the nose. The sinuses may fill with thick secretions. Teenagers often have slowed growth, delayed puberty, and declining physical endurance.
Infection is also a major problem.
Recurrent bronchitis and pneumonia gradually destroy the lungs. Death usually results from a combination of respiratory failure and a failing heart caused by the underlying lung disease. About 2 to 3 percent of people with cystic fibrosis develop insulin-dependent diabetes because the scarred pancreas can no longer produce enough insulin. The blockage of bile ducts by thick secretions can lead to inflammation of the liver and eventually to cirrhosis. These abnormal veins can bleed copiously.