cystic fibrosis FAQ

Cystic fibrosis (CF) is a genetic disorder, which means you get it from your parents at birth. It affects your lungs, pancreas, and other organs. CF changes the way chloride (salt) moves through the cells of your body. This causes the mucus (which should be thin and slippery) in various organs to become thick and sticky. Over time, this thick mucus builds up inside your airways, making it hard to breathe. The mucus traps germs and leads to infections and inflammation. It can also cause severe, long-term damage to the lungs and lead to respiratory failure (inability to breathe normally) and death. In the pancreas, the thick mucus caused by CF prevents the release of digestive enzymes when you eat. This leads to malnutrition and poor growth. CF can also cause liver disease, reproductive problems, and cystic fibrosis-related diabetes (CFRD). More than 40,000 people in the U.S. live with CF. Doctors diagnose about 1,000 new cases each year. Today, more than half of the CF population is aged 18 or older, and new treatments have expanded the life expectancy by decades.

You might want to take a friend or family member with you to the appointment to help you remember information. Before your appointment, make a list of: Symptoms and when they started. Include anything that makes symptoms worse or better. All medicines, vitamins, herbs and supplements that you or your child take. Include the doses. Family history, such as whether anyone in your family has cystic fibrosis. Treatment you or your child have had for CF, if any. Include what the treatment was and if it helped. Any other medical conditions and their treatments. Questions to ask your healthcare professional. Questions to ask may include: What is likely causing these symptoms? What kinds of tests are needed? What treatment do you recommend? I or my child have other health conditions. How will cystic fibrosis affect them? Are there any limits needed? Feel free to ask other questions during your appointment.

After getting detailed information about the symptoms and your family's medical history, your healthcare professional may order tests to help with diagnosis and plan treatment. Your healthcare professional also may ask questions, such as: What symptoms are you or your child having? When did the symptoms start? Does anything make the symptoms better or worse? Has anyone in your family ever had cystic fibrosis? Has growth been average and weight been stable? Cystic fibrosis. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/health/cystic-fibrosis. Accessed Aug. 8, 2024. Bronchiectasis. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/health/bronchiectasis. Accessed Aug. 8, 2024. FAQs: Cystic fibrosis: Prenatal screening and diagnosis. American College of Obstetricians and Gynecologists. https://www.acog.org/womens-health/faqs/cystic-fibrosis-prenatal-screening-and-diagnosis. Accessed Aug. 8, 2024. Ferri FF. Cystic fibrosis. In: Ferri's Clinical Advisor 2025. Elsevier; 2025. https://www.clinicalkey.com. Accessed Aug. 8, 2024. Kliegman RM, et al., eds. Cystic fibrosis. In: Nelson Textbook of Pediatrics. 22nd ed. Elsevier; 2025. https://www.clinicalkey.com. Accessed Aug. 8, 2024. Kellerman RD, et al. Cystic fibrosis. In: Conn's Current Therapy 2024. Elsevier; 2024. https://www.clinicalkey.com. Accessed Aug. 8, 2024. Lockwood CJ, et al., eds. Respiratory diseases in pregnancy. In: Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice. 9th ed. Elsevier; 2023. https://www.clinicalkey.com. Accessed Aug. 8, 2024. Ong T, et al. Cystic fibrosis: A review. JAMA. 2023; doi:10.1001/jama.2023.8120. Rubin R. Tackling the misconception that cystic fibrosis is a "white people's disease." JAMA. 2021; doi:10.1001/jama.2021.5086. Care centers. Cystic Fibrosis Foundation. https://www.cff.org/managing-cf/care-centers. Accessed Aug. 8, 2024. Trikafta (prescribing information). Vertex Pharmaceuticals Inc.; 2023. https://www.trikafta.com/. Accessed Aug. 8, 2024. Symdeko (prescribing information). Vertex Pharmaceuticals Inc.; 2023. https://www.symdeko.com/. Accessed Aug. 8, 2024. Orkambi (prescribing information). Vertex Pharmaceuticals Inc.; 2023. https://www.orkambi.com/. Accessed Aug. 8, 2024. Kalydeco (prescribing information). Vertex Pharmaceuticals Inc.; 2023. https://www.kalydeco.com/. Accessed Aug. 8, 2024. Pilewski JM. Update on lung transplantation for cystic fibrosis. Clinics in Chest Medicine. 2022; doi:10.1016/j.ccm.2022.07.002. Fridell JA, et al. Pancreas transplantation for cystic fibrosis: A frequently missed opportunity. Clinical Transplantation. 2021; doi:10.1111/ctr.14371. Wadsworth LE, et al. Non-invasive ventilation is associated with long-term improvements in lung function and gas exchange in cystic fibrosis adults with hypercapnic respiratory failure. Journal of Cystic Fibrosis. 2021; doi:10.1016/j.jcf.2021.05.011. Allscripts EPSi. Mayo Clinic. Medical review (expert opinion). Mayo Clinic. Oct. 18, 2024.

If you or your child has symptoms of cystic fibrosis — or if someone in your family has CF — talk with your healthcare professional about testing for the condition. Make an appointment with a doctor who has skills and experience in treating CF. CF requires regular follow-up with your healthcare professional, at least every three months. Call your healthcare professional if you have new or worsening symptoms, such as more mucus than usual or a change in the mucus color, lack of energy, weight loss, or severe constipation. Get medical care right away if you're coughing up blood, have chest pain or trouble breathing, or have severe stomach pain and bloating. Call 911 or your local emergency number or go to the emergency department at a hospital if: You're having a hard time catching your breath or talking. Your lips or fingernails turn blue or gray. Others notice that you're not mentally alert.

Learn more from pulmonologist Sarah Chalmers, M.D. Cystic fibrosis (CF) is a condition passed down in families that causes damage to the lungs, digestive system and other organs in the body. CF affects the cells that make mucus, sweat and digestive juices. These fluids, also called secretions, are usually thin and slippery to protect the body's internal tubes and ducts and make them smooth pathways. But in people with CF, a changed gene causes the secretions to become sticky and thick. The secretions plug up pathways, especially in the lungs and pancreas. CF gets worse over time and needs daily care, but people with CF usually can attend school and work. They often have a better quality of life than people with CF had in past decades. Better screening and treatments mean that people with CF now may live into their mid- to late 50s or longer, and some are being diagnosed later in life.

In rare cases, conditions other than CF may result in high chloride levels on a sweat test. These conditions include hypothyroidism , nephrogenic diabetes insipidus , and Addison disease .

A sweat test is used to diagnose cystic fibrosis (CF).

You don't need any special preparations for a sweat test, but you should avoid applying any creams or lotions to the skin for 24 hours before the test.

To do a sweat test, a health care professional will collect a sample of sweat from you or your child. This takes about an hour and usually includes the following steps:

Chloride in sweat is measured in mmol/L (millimoles of chloride per liter of sweat):

A sweat test measures the amount of chloride in your sweat . Chloride is a type of electrolyte . Electrolytes are electrically charged minerals  that help control the amount of fluids and the balance of acids and bases (pH balance) in your body. Chloride and sodium form the salt found in your sweat.

A sweat test may be ordered if your health care provider suspects you or your child has cystic fibrosis (CF). It's most commonly ordered for newborns. In the United States, babies have newborn screening  tests to check for a variety of conditions, including CF. If a screening test shows that your baby may have CF, a sweat test will be needed to make a diagnosis.

There is no known risk to a sweat test. The electrode may cause a tingling or tickling sensation from the electric current, but this is not painful.

The symptoms of cystic fibrosis vary. Some children will have symptoms at birth, while others may not have symptoms for weeks, months, or even years. The severity of symptoms also varies, with some children showing only mild digestive and lung problems and others having severe food-absorption problems and life-threatening breathing complications. The most common symptoms of cystic fibrosis are: Salty-tasting skin , which parents notice when they kiss their child Frequent coughing , wheezing , or bouts of pneumonia or sinusitis Difficulty breathing that keeps getting worse Big appetite but poor weight gain Bulky, smelly, greasy bowel movements Over time, the symptoms of cystic fibrosis can worsen and may include: Chronic productive cough, recurrent lung infections Obstructive lung disease ( emphysema ) Chronic nasal congestion and sinus infections Pancreatitis , a painful inflammation of the pancreas Liver disease Diabetes Gallstones

Alyftrek is a specialty medicine. This means that you can only get it from a specialty pharmacy and it may require prior authorization from your insurance company.

The effectiveness and safety of Alyftrek for cystic fibrosis was studied in two randomized trials (Trials VX20-121-102 and VX20-121-103). These studies compared Alyftrek to another standard treatment for cystic fibrosis ( elexacaftor /tezacaftor/ivacaftor). People in the studies first received elexacaftor/tezacaftor/ivacaftor for four weeks, then were assigned to continue this treatment or switch to Alyftrek for 52 weeks. Trial VX20-121-102 included 398 people with F508del-minimal function genotypes. The median (middle) age was 31 and 41% of people were female; most people in the study were White (97%), while 1% were Black or African American, and <1% were Asian. Trial VX20-121-103 included 573 people with F508del-F508del, F508del-residual function, F508del-gating, or other responsive mutations. The median age was 33.1 and 49% of people in the study were female. Most people were White (93%), 1% were Black or African American, and <1% each were Southeast Asian, other Asian, or American Indian/Alaska Native. The study found that Alyftrek was similar to elexacaftor/tezacaftor/ivacaftor in improving lung function (measured by forced expiratory volume in 1 second [FEV1 %]), with similar results seen in both studies. Additionally, Alyftrek led to greater reductions in sweat chloride, a key measure of CFTR function, in both studies. The results of these studies suggest that Alyftrek is a promising alternative to elexacaftor/tezacaftor/ivacaftor, offering similar lung function benefits and helping CFTR to work better. The safety profile of Alyftrek was similar to that of elexacaftor/tezacaftor/ ivacaftor . The most common side effects included worsening lung infections (28%), cough (23%), COVID-19 (22%), and the common cold (nasopharyngitis; 21%). Serious side effects were similar between groups, with 14% of people treated with Alyftrek and 16% of people treated with standard treatment experiencing severe reactions. High liver enzymes were slightly more common in the Alyftrek group, but overall safety findings were similar to those seen in other studies. Your results may differ from what was seen in clinical studies.

Your health care provider will decide the correct dose of Alyftrek based on your age and weight. Alyftrek is a tablet that is taken by mouth. It should be swallowed whole with food that contains fat, such as eggs, nuts, meats, or dairy products, to help the body absorb the medicine properly. The treatment plan usually follows these steps after receiving the recommended liver evaluations and tests: For people aged 6 to <12 years (<40 kg): Take three tablets (vanzacaftor 4 mg/tezacaftor 20 mg/ deutivacaftor 50 mg) once daily with fat-containing food. For people aged 6 to <12 years (≥40 kg) or ≥12 years: Take two tablets (vanzacaftor 10 mg/tezacaftor 50 mg/deutivacaftor 125 mg) once daily with fat-containing food. Dose adjustments may be needed in people with liver problems. Alyftrek should be taken at the same time each day to maintain steady levels of the medicine in the body. Keep all appointments with your health care provider before and while taking Alyftrek. Your health care provider may monitor how well your liver is working.

The most common side effects of Alyftrek are cough, common cold, sinus infection , headache, sore throat , flu, feeling tired, skin rash, and changes in liver enzyme levels. If you experience a serious allergic reaction, such as difficulty breathing, swelling of the face, or severe dizziness, seek medical attention immediately. Liver problems, such as increased liver enzyme levels, may occur. Your doctor will monitor liver function with routine blood tests. Report any signs of yellowing skin or eyes ( jaundice ), dark urine (pee), or unexplained tiredness to your health care provider. Regular eye exams are also recommended since Alyftrek may cause cataracts , especially in younger people. Routine check-ups can help detect early changes in vision. These are not all of the possible side effects. Talk with your health care provider if you are having symptoms that bother you. Depending on the severity of your side effects, your health care provider may pause, reduce the dose, or permanently discontinue treatment with Alyftrek. In the U.S., you can also report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088.

Overall, Alyftrek for cystic fibrosis treatment has been studied in a variety of people. Adults Adolescents Males and females Asian, Black, and White people

Your health care provider will monitor your progress while you are taking Alyftrek to make sure the treatment is effective. One key test used to measure progress is lung function testing (like FEV₁%), which checks how well your lungs are working. If Alyftrek is working, your FEV₁% may get better or remain the same over time. Another important measure is sweat chloride levels. Higher sweat chloride levels are a sign of cystic fibrosis, and Alyftrek may help lower these levels by helping the CFTR protein work better. Your health care provider may order sweat chloride tests to track improvements. In addition to lab tests, you may notice fewer lung infections, better breathing, less coughing, and increased energy levels. Your health care provider will also monitor for any side effects and may adjust your treatment plan if needed. Always follow up with your health care team to discuss any changes in symptoms or concerns about your treatment. Do not stop taking Alyftrek without talking to your health care provider first. Your symptoms may get worse again if you stop or change any of your medicines.