Cystic fibrosis is a disease that causes thick, sticky mucus to build up in the lungs, digestive tract, and other areas of the body. It is one of the most common chronic lung diseases in children and young adults. It is a life-threatening disorder.
Cystic fibrosis (CF) is a disease that is passed down through families. It is caused by a defective gene that makes the body produce abnormally thick and sticky fluid, called mucus. This mucus builds up in the breathing passages of the lungs and in the pancreas.
The buildup of mucus results in life-threatening lung infections and serious digestion problems. The disease may also affect the sweat glands and a man's reproductive system.
Many people carry a CF gene, but do not have symptoms. This is because a person with CF must inherit 2 defective genes, 1 from each parent. Some Americans have the CF gene. It is more common among those of northern or central European descent.
Most children with CF are diagnosed by age 2, especially as newborn screening is performed across the United States. For a small number, the disease is not detected until age 18 or older. These children often have a milder form of the disease.
Parents can pass all kinds of different traits to their children, from blue eyes to blonde hair. Sometimes, parents can also pass the genes for certain diseases to their kids. Cystic fibrosis is one very serious inherited disease that makes it hard for children to breathe and digest food. Let's talk about cystic fibrosis. Genes are the coded instructions that tell our bodies how to operate. Usually, the code is correct and everything runs smoothly. But sometimes, the code is incorrect because of a defective gene or genes. In the case of cystic fibrosis, a faulty gene causes the body to produce an abnormally thick, sticky fluid called mucus. This mucus clogs the lungs, making it hard to breathe. It also gets stuck in the pancreas, making it harder for the body to break down and digest food. Millions of Americans carry the cystic fibrosis, or CF gene. Fortunately, most of them don't have cystic fibrosis. That's because you need to inherit one faulty gene from each parent to actually get the disease. Kids who are born with cystic fibrosis start showing signs very early. Newborns don't grow or gain weight as quickly as they should, and they don't make bowel movements because their bodies aren't digesting food properly. As these children get older, they may have symptoms like coughing and fatigue from the mucus in their lungs, and nausea and stomach pain from the mucus in their pancreas. They'll also get pneumonia and other lung infections more often than normal. So, you may now be asking, how do you know if your child has cystic fibrosis? Doctors diagnose cystic fibrosis using a blood test that looks for the CF gene. There is also a sweat test, which looks for saltier-than-normal sweat, another symptom of cystic fibrosis. Doctors may use other tests, such as a chest x-ray or upper GI series, to check for lung and bowel problems caused by CF. It's a good idea to get treated at a center that specializes in cystic fibrosis because they're up on all the latest therapies. For lung problems, treatments include inhaled medicines to open the airways, medicine to thin mucus and make it easier to cough up, and antibiotics to prevent lung infections. Some people may eventually need a lung transplant. For bowel problems, you'll need to eat a special diet that's higher in protein and calories to make up for the nutrients you're losing. You may also take vitamin supplements. The outlook for people with cystic fibrosis is better today than ever before. Thanks to new treatments, people with this disease can live well into adulthood. They can go to school, play sports, and get a job like everyone else. But because the symptoms of cystic fibrosis are so serious, it's very important to stay on top of treatment, and to call the doctor right away if symptoms get worse. Anyone with a family history of the disease may want to get screened for the CF gene before they decide to have children.
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
- Nasal congestion caused by nasal polyps
- Repeated episodes of pneumonia (symptoms of pneumonia in someone with cystic fibrosis include fever, increased coughing and shortness of breath, increased mucus, and loss of appetite)
- Sinus pain or pressure caused by infection or polyps
Symptoms that may be noticed later in life:
- Infertility (in men)
- Repeated inflammation of the pancreas (pancreatitis)
- Respiratory symptoms
- Clubbed fingers
Exams and Tests
A blood test is done to help detect CF. The test looks for changes in the CF gene. Other tests used 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 person's sweat is a sign of the disease.
Other tests that identify problems that can be related to CF include:
- Chest x-ray or CT scan
- Fecal fat test
- Lung function tests
- Measurement of pancreatic function (stool pancreatic elastase)
- Secretin stimulation test
- Trypsin and chymotrypsin in stool
- Upper GI and small bowel series
- Lung cultures (obtained by sputum, bronchoscopy or throat swab)
If you have cystic fibrosis, it's important to eat specific foods and take the right supplements. Let's talk about cystic fibrosis diet. So, why is your diet important? Cystic fibrosis is a disease that causes thick, sticky mucus to build up in your lungs and digestive tract. You need to eat high-calorie, high-protein foods throughout the day to maintain a normal weight because your disease makes it hard to get enough calories from the foods you eat. How do you get the right diet? First of all, you'll need to take a good multivitamin. Make sure it contains vitamins A, D, E, and K. You'll probably need to take pancreatic enzymes, too. These enzymes help your body absorb fat and protein. A good practice is to eat whenever you are hungry. This probably means you'll need to eat several small meals a day. Keep a variety of nutritious snacks around. Try to snack on something every hour, like cheese and crackers, muffins, or trail mix. Make an effort to eat regularly, even if it's only a few bites. Nutritional supplement milkshakes are good to keep on hand. Here's a recommended diet for someone with cystic fibrosis, Add grated cheese to your meals. Drink whole milk. Use enriched milk in cooking. Eat peanut butter. Put it on bread, use it for a dip, and cook with it. Put a teaspoon of butter on hot foods. Dab sour cream or yogurt on vegetables. Eat breaded meat, chicken, and fish. If you get the right balance of extra protein, fat, and calories, and take the right supplements, you can lead a much healthier life.
An early diagnosis of CF and treatment plan can improve both survival and quality of life. Follow-up and monitoring are very important. When possible, care should be received at a cystic fibrosis specialty clinic. When children reach adulthood, they should transfer to a cystic fibrosis specialty center for adults.
Treatment for lung problems includes:
- Antibiotics to prevent and treat lung and sinus infections. They may be taken by mouth, or given in the veins or by breathing treatments. People with CF may take antibiotics only when needed, or all the time. Doses are often higher than normal.
- Inhaled medicines to help open the airways.
- Other medicines that are given by a breathing treatment to thin mucus and make it easier to cough up are DNAse enzyme therapy and highly concentrated salt solutions (hypertonic saline).
- Flu vaccine and pneumococcal polysaccharide vaccine (PPV) yearly (ask your health care provider).
- Lung transplant is an option in some cases.
- Oxygen therapy may be needed as lung disease gets worse.
Lung problems are also treated with therapies to thin the mucus. This makes it easier to cough the mucus out of the lungs.
These methods include:
- Activity or exercise that causes you to breathe deeply
- Devices that are used during the day to help clear the airways of too much mucus
- Manual chest percussion (or chest physiotherapy), in which a family member or a therapist lightly claps the person's chest, back, and area under the arms
Treatment for bowel and nutritional problems may include:
- A special diet high in protein and calories for older children and adults
- Pancreatic enzymes to help absorb fats and protein, which are taken with every meal
- Vitamin supplements, especially vitamins A, D, E, and K
- Your provider can advise other treatments if you have very hard stools
Ivacaftor, lumacaftor, tezacaftor, and elexacaftor are medicines that treat certain types of CF.
- They improve the function of one of the defective genes that causes CF.
- Up to 90% of patients with CF and eligible for one or more of these medicines alone or in combination.
- As a result, there is less buildup of thick mucus in the lungs. Other CF symptoms are improved as well.
Care and monitoring at home should include:
- Avoiding smoke, dust, dirt, fumes, household chemicals, fireplace smoke, and mold or mildew.
- Giving plenty of fluids, especially to infants and children in hot weather, when there is diarrhea or loose stools, or during extra physical activity.
- Exercising 2 or 3 times each week. Swimming, jogging, and cycling are good options.
- Clearing or bringing up mucus or secretions from the airways. This must be done 1 to 4 times each day. Patients, families, and caregivers must learn about doing chest percussion and postural drainage to help keep the airways clear.
- No contact with other people with CF is recommended as they can exchange infections (does not apply to family members).
You can ease the stress of illness by joining a cystic fibrosis support group. Sharing with others who have common experiences and problems can help your family to not feel alone.
Most children with CF stay in good health until they reach adulthood. They are able to take part in most activities and attend school. Many young adults with CF finish college or find jobs.
Lung disease eventually worsens to the point where the person is disabled. Today, the average life span for people with CF who live to adulthood is about 44 years.
Death is most often caused by lung complications.
The most common complication is chronic respiratory infection.
Other complications include:
- Bowel problems, such as gallstones, intestinal blockage, and rectal prolapse
- Coughing up blood
- Chronic respiratory failure
- Liver disease or liver failure, pancreatitis, biliary cirrhosis
- Nasal polyps and sinusitis
- Osteoporosis and arthritis
- Pneumonia that keeps coming back
- Right-sided heart failure (cor pulmonale)
- Colorectal cancer
When to Contact a Medical Professional
Call your provider if an infant or child has symptoms of CF, and experiences:
- Fever, increased coughing, changes in sputum or blood in sputum, loss of appetite, or other signs of pneumonia
- Increased weight loss
- More frequent bowel movements or stools that are foul-smelling or have more mucus
- Swollen belly or increased bloating
Call your provider if a person with CF develops new symptoms or if symptoms get worse, particularly severe breathing difficulty or coughing up blood.
CF cannot be prevented. Screening those with a family history of the disease may detect the CF gene in many carriers.
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Last reviewed on: 2/24/2022
Reviewed by: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.