Understanding Cystic Fibrosis -- Diagnosis and Treatment

Medically Reviewed by Dan Brennan, MD on March 05, 2023

Diagnosing cystic fibrosis in an unborn baby is possible through genetic testing. The National Institutes of Health recommends that genetic testing for cystic fibrosis be offered to all expectant couples or those still planning a pregnancy, especially if they have a family history of the disease.

Every state now screens newborns for cystic fibrosis. Blood testing will show whether your baby's pancreas is functioning the way it should.

A child who shows poor growth and has repeated lung or sinus infections or both should be tested for cystic fibrosis. The standard test for cystic fibrosis is the quantitative sweat chloride test, or "sweat test," which measures the amount of salt in the sweat. Because newborns don't sweat, an immunoreactive trypsinogen test (IRT) may be used instead. This test involves drawing blood and looking for a specific protein called trypsinogen. A positive IRT test may be confirmed at a later date with genetic testing or a sweat test.

Other tools that help with diagnosis include chest X-rays and lung function tests, which may show lung problems common in cystic fibrosis. Tests of stool samples may show digestive problems.


Treatment for cystic fibrosis focuses on both lung health and digestion.

Treating Lung Problems
Doctors will focus on preventing lung infections. Daily chest physiotherapy (CPT), also known as percussion and postural drainage, helps to loosen mucus in the lungs and helps with coughing. During CPT, the person is put into a position that helps drainage, and then all areas of the lungs are "percussed" by clapping on the person's back with a cupped hand. Family members can perform CPT on small children, while older children and young adults can learn to do it themselves. CPT is usually performed twice a day, though it may be done more frequently when the person has an active lung infection. Treatments using vibrating vests are also being widely used and appear to be better in many children, though expensive.

Regular exercise also helps to loosen and move secretions and maintain lung and heart fitness.

Antibiotics are crucial to treating cystic fibrosis lung infections.

Mucus-thinning drugs help a person cough up mucus in the lungs.

Anti-inflammatory drugs help lower inflammation in the lungs. Tezacaftor /ivacaftor (Symdeko) is a medication available in a tablet that can help air move easier through the lungs, allowing you to blow more air out of your lungs. This medicine is available to anyone 6 years and older.

Treating Digestive Problems
People with CF need to eat a well-balanced, high-calorie, high-protein diet. Their reduced absorption of nutrients often means that as children, they must get up to 150% of the recommended daily allowances to meet their growth needs. Multivitamins and supplements of vitamins A, D, E, and K are also important. To help digestion, people with cystic fibrosis need to take pancreatic enzymes before every meal and snack and extra enzymes to help digest high-fat foods. Those with severe digestive problems may need supplemental feedings with specialized, high-calorie formulas either with a feeding tube or, in rare cases, through a vein.

Gene Therapy
Gene therapy attacks the cause of cystic fibrosis rather than just treating the symptoms. An exciting new advancement, Kalydeco (ivacaftor), a drug that targets the underlying genetic mutation that causes cystic fibrosis, shows promise. Four percent of those with the disease -- about 1,200 people in the U.S. -- have the specific gene defect that Kalydeco treats. The drug is approved for people ages 4 months and older. 

Trikafta is another gene therapy drug that combines ivacaftor with elexacaftor and tezacafto. It is approved for patients ages 6 years and older. 

Some cystic fibrosis patients have had lung transplants to replace failing lungs.

If both parents are carriers of the cystic fibrosis gene, they may wish to consider their chances of having a child with cystic fibrosis. Genetic testing of the unborn baby for cystic fibrosis can be done in the uterus but requires taking fluid or tissue samples from the womb (amniocentesis or chorionic villus sampling). Once a child is born, there are no treatments available that can prevent cystic fibrosis from developing.

Show Sources


Cystic Fibrosis Foundation. 

The Mayo Clinic. 

The New England Journal of Medicine.


FDA: Drug Trials Snapshots: SYMDEKO. News Release.

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