Signs and symptoms associated with CF include:

• Frequent coughing, chronic cough and sputum production
• Repeated or persistent chest infections such as bronchitis or pneumonia
• Abdominal pain or discomfort
• In newborns, meconium ileus
• Chronic diarrhea and foul-smelling, greasy stools
• Weight loss or malnutrition
• Failure to thrive — large appetite but failure to gain weight or grow at a normal rate
• Decreased levels of protein in the blood and edema

CF interferes with electrolyte and fluid balance in the body. In most CF patients, sweat contains up to five times more salt (sodium chloride) than normal. Losing excess sodium and chloride can affect the heart rhythm and may sometimes cause shock.

In patients with CF, lubricating mucus in the lungs becomes thick and sticky, providing a breeding ground for microorganisms, causing frequent respiratory infections. These must be aggressively treated with intravenous, oral, and/or inhaled antibiotics. Much of the morbidity associated with CF is due to respiratory infections and lung complications.

Mucus plugs in the pancreas lead to blocked ducts, resulting in malabsorption because pancreatic enzymes are prevented from traveling to the intestine to digest proteins and fats. This can lead to vitamin deficiencies and malnutrition. Oral pancreatic enzyme supplements and replacement of fat-soluble vitamins A, D, E and K can ease these symptoms, along with a low fat, high protein diet. If pancreatic damage is sufficient, some CF patients eventually become diabetic.

Other problems associated with CF include:

• Gallstones
• Pancreatitis
• Delayed growth and delayed sexual development at puberty
• Enlargement or rounding (clubbing) of the fingertips and toes
• Chronic hepatic disease and biliary cirrhosis
• Rectal prolapse (protrusion of the rectum through the anus)
• Male infertility (obstructive azoospermia)