What's cystic fibrosis?
Cystic fibrosis is an inherited condition caused by changes in the CFTR gene. CFTR normally moves salt and water across cell surfaces; when it fails, secretions become thick and sticky, mainly damaging the lungs and the pancreas.
| Also indexed as | OMIM:219700, MONDO:0009061 |
|---|---|
| Features mapped | 13 |
| Treatments mapped | 5 |
| Published sources | 11 |
| Last reviewed | 2026-08-04 |
Signs and symptoms
Elevated sweat chloride
A high level of chloride in sweat is the hallmark diagnostic finding in cystic fibrosis (values around 100 mmol/L are well above the normal range).
Recurrent pneumonia
Additional clinical findings included chronic right-sided otitis media, conjunctivitis, recurrent pneumonia, bilateral conductive hearing loss, astigmatism, and primary adenitis.
Recurrent bronchopulmonary infections
Thick airway mucus leads to repeated and chronic lung infections, often with bacteria such as Pseudomonas that are hard to clear, driving progressive lung damage.
Male infertility
Most men with cystic fibrosis are infertile because the tube that carries sperm (the vas deferens) is usually absent from birth. This does not affect sexual function, and fathering children is often still possible with assisted reproduction.
Autosomal recessive inheritance
Cystic fibrosis is inherited in an autosomal recessive pattern, occurring when a child inherits a changed copy of CFTR from both parents.
Bronchiectasis
For people with COPD or bronchiectasis, having Pseudomonas aeruginosa bacteria in the lungs can make lung inflammation worse and is associated with poorer health outcomes, including a greater risk of dying from their disease.
Chronic lung disease
Conditions such as COPD, cystic fibrosis, and bronchiectasis cause thick, sticky mucus to build up in the lungs. This mucus is difficult for the body to clear, making it easier for infections to develop and leading to ongoing inflammation.
Exocrine pancreatic insufficiency
The pancreas often cannot deliver its digestive enzymes (exocrine pancreatic insufficiency), so fat is poorly absorbed and stools become greasy, affecting growth and nutrition.
Ileus
Patients who had two copies of the same cystic fibrosis mutation were more likely to experience certain complications, including a bowel blockage at birth (meconium ileus) and diabetes related to cystic fibrosis.
Pancreatitis
People with CFTR-related disorders commonly experience repeated attacks of pancreatitis, a painful condition caused by inflammation of the pancreas.
Cirrhosis
Liver problems related to cystic fibrosis generally develop gradually over many years. Liver damage caused by CFTR modulator drugs is more likely to happen suddenly, with symptoms such as yellowing of the skin or eyes and elevated liver enzymes appearing soon after treatment begins.
Biliary cirrhosis
Liver disease caused by cystic fibrosis usually develops gradually over many years. Liver damage caused by certain cystic fibrosis medications is more likely to occur suddenly, often soon after starting the drug, and can cause jaundice and abnormal liver tests.
Meconium ileus
Meconium ileus, a blockage of the newborn bowel by thick meconium, can be the first sign of cystic fibrosis at birth.
How it is diagnosed
Cystic fibrosis
Diagnosed using: Sweat chloride test.
“…sweat chloride test…”
Treatment and management
What the research describes, not a recommendation. Treatment decisions belong with your clinician.
This covers treatments that appear in the published research mapped here. Investigational and experimental therapies are not included, so their absence is a boundary of this map, not a sign they do not exist.
CFTR modulators
CFTR modulators (such as elexacaftor/tezacaftor/ivacaftor) act on the faulty CFTR protein itself and have become the cornerstone of cystic fibrosis management for eligible genotypes.
Used to help with: Cystic fibrosis.
“As CFTR modulators become the cornerstone of CF management, vigilance for hepatotoxicity is critical.”
Dornase alfa
Dornase alfa is an inhaled medicine that thins the thick mucus in the lungs by breaking down DNA released by inflammatory cells, making it easier to clear. It is a long-standing part of cystic fibrosis lung care.
Used to help with: Cystic fibrosis.
“…dornase alfa remains a cornerstone in CF…”
dornase alfa
Dornase alfa is an inhaled enzyme that breaks down extracellular DNA, which is a major reason the mucus in cystic fibrosis is so thick and sticky. Thinning that mucus helps clear the airways.
Used to help with: Chronic lung disease.
“Finally, dornase alfa exerts an enzymatic effect on extracellular DNA, a key contributor to the tenacity of mucus in cystic fibrosis.”
elexacaftor/tezacaftor/ivacaftor
Elexacaftor-tezacaftor-ivacaftor (ETI) is a triple CFTR modulator therapy. Since it became available from 2018-19, it has driven marked improvements in cystic fibrosis treatment.
Used to help with: Cystic fibrosis.
“From 2014 to 2024, the adult cystic fibrosis population in Europe expanded substantially due to marked improvements in treatment, particularly following the availability of ETI triple therapy from 2018-19 onwards.”
pancreatic enzyme replacement therapy
Pancreatic enzyme replacement therapy (PERT) supplies the digestive enzymes the pancreas cannot release. In cystic fibrosis it is started when there are signs of pancreatic insufficiency.
Used to help with: Cystic fibrosis.
“Clinicians must have a high suspicion for cystic fibrosis among patients with clinical symptoms of pancreatic insufficiency, and pancreatic enzymatic replacement therapy (PERT) must be urgently initiated.”
How to read the evidence labels
Where this comes from
This guide is built from 11 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.
Take it further
Printed, source-linked documents built from this condition's graph — ready to bring to an appointment or attach to a coverage request. Every claim carries its published source, the same as this guide.