Clinical Manifestations

Clinical manifestations of cystic fibrosis

Cystic fibrosis is a disorder that affects multiple body systems1 and can progress with age, requiring multidisciplinary care and age-specific expertise to treat patients appropriately.

Classical signs and symptoms of cystic fibrosis are described by the Consensus Guidelines from the Cystic Fibrosis Foundation.


Clinical manifestations can change with age of the patient2

Please click on the age range below (age in years) to see when the clinical manifestations of cystic fibrosis begin.

Human BodyButtonAbsence of vas deferensReproductive systemMeconium ileusGutPancreatic exocrine insufficiencyPancreasAbnormal liver function test resultsLiverStaphylococcus aureusPredominant infectionsEarly mucinous plugging;BronchiectasisLung and airwaysCirrhosisLiverStaphylococcus aureus;IntermittentPseudomonas aeruginosaPredominant infectionsEstablished bronchiectasisLung and airwaysArthropathy and cystic fibrosis–related bonedisease (osteoporosis)OtherDistal intestinal obstruction syndromeGutCystic fibrosis–related diabetes mellitusPancreasPortal hypertension (5–10%)LiverPseudomonas aeruginosa;Other non-fermenting Gram-negative bacteria;Allergic bronchopulmonary aspergillosisPredominant infectionsEstablished bronchiectasis with haemoptysis;PneumothoraxLung and airwaysLiver transplantLiverProgressive respiratory failure;Lung transplantLung and airwaysLung and airwaysEarly mucinous plugging;BronchiectasisPredominant infectionsStaphylococcus aureusLiverAbnormal liver function testresultsPancreasPancreatic exocrineinsufficiencyGutMeconium ileusReproductive systemAbsence of vas deferensLung and airwaysEstablished bronchiectasisPredominant infectionsStaphylococcus aureus;IntermittentPseudomonasaeruginosaLiverCirrhosisLung and airwaysEarly mucinous plugging;BronchiectasisPredominant infectionsPseudomonas aeruginosa;Other non-fermenting Gram-negativebacteria; Allergic bronchopulmonaryaspergillosis;LiverPortal hypertension (5–10%)PancreasCystic fibrosis–relateddiabetes mellitusGutDistal intestinal obstructionsyndromeOtherArthropathy and cysticfibrosis–related bone disease(osteoporosis)Lung and airwaysProgressive respiratory failure;Lung transplantLiverLiver transplant

Morbidity and mortality

Morbidity and mortality are mainly caused by bronchiectasis, small airways obstruction, and progressive respiratory impairment. Important comorbidities caused by epithelial cell dysfunction occur in the pancreas (malabsorption), liver (biliary cirrhosis), sweat glands (heat shock), and vas deferens (infertility).2


Algorithm for differential diagnosis of cystic fibrosis1



  1. Farrell PM, et al. Diagnosis of cystic fibrosis: consensus guidelines from the Cystic Fibrosis Foundation. J Pediatr. 2017;181S:S4-S15.
  2. Elborn JS, Cystic fibrosis. Lancet. 2016;388(10059):2519-2531. 

Mucus contributes to early small airways obstruction

The animations illustrate the airflow in a small airway vessel during inspiration (widening) and expiration (narrowing) under healthy and cystic fibrosis conditions. In a healthy small airway vessel, the laminar airflow passes smoothly alongside the mucosal folds. In cystic fibrosis, however, the thickening of the mucosa and the presence of sputum in the vessel lumen (patches) cause increased resistance and air turbulence. By using a stethoscope, this air turbulence can be heard as a crackling and wheezing sound.

Airflow through a small airway of a healthy person

Airflow through a small airway in a cystic fibrosis patient