Because there are more than 1,000 mutations of the CF gene, symptoms differ from person to person.

Symptoms in newborns may include:

• Delayed growth
• Failure to gain weight normally during childhood
• No bowel movements in first 24 to 48 hours of life
• Salty-tasting skin

Symptoms related to bowel function may include:

• Belly pain from severe constipation
• Increased gas, bloating, or a belly that appears swollen (distended)
• Nausea and loss of appetite
• Stools that are pale or clay colored, foul smelling, have mucus, or that float
• Weight loss

Symptoms related to the lungs and sinuses may include:

• Coughing or increased mucus in the sinuses or lungs
• Fatigue
• Nasal congestion caused by nasal polyps
• Recurrent episodes of pneumonia. Symptoms in someone with cystic fibrosis include:
  • Fever
  • Increased coughing
  • Increased shortness of breath
  • Loss of appetite
  • More sputum
• Sinus pain or pressure caused by infection or polyps

A blood test is available to help detect CF. The test looks for variations in a gene known to cause the disease. Other tests use to diagnose CF include:

• Immunoreactive trypsinogen (IRT) test is a standard newborn screening test for CF. A high level of IRT suggests possible CF and requires further testing.
• Sweat chloride test is the standard diagnostic test for CF. A high salt level in the patient's sweat is a sign of the disease.

Other tests that identify problems that can be related to cystic fibrosis include:

• Chest x-ray or CT scan
• Fecal fat test
• Lung function tests
• Measurement of pancreatic function
• Secretin stimulation test
• Trypsin and chymotrypsin in stool
• Upper GI and small bowel series