Page title ‘Glossary of terms’ with illustration displaying a person holding an open laptop, sitting on top of two giant books, an upright blue book labelled ‘A-Z’ on their left side, and a purple plant on their right side, with a green background


Cardiovascular exercise: Exercise that raises your heart and breathing rate to improve overall fitness by keeping the heart, lungs and circulatory system healthy. It is also referred to as aerobic exercise.1,2 For inspiration on how to get started and continue your training, visit CF Exercise.

CFTR gene mutations: We know of over 2000 different CFTR gene mutations, of which at least 401 cause CF.3,4 If both CFTR genes you inherit have a mutation that causes CF, you are born with CF. People with CF can either have two copies of the same CFTR mutation, or two copies with different CFTR mutations.3 For more information on CFTR gene mutations, visit Causes of CF.

CFQ-R: The Cystic Fibrosis Questionnaire – Revised (CFQ-R) is used to measure the impact of a treatment on a person’s overall health, daily life, wellbeing and symptoms.5

Chloride ion: Chloride plays an important role in the body. The movement of chloride ions in and out of cells helps control the movement of water in the body. This is needed to keep mucus thin and watery to protect our airways and digestive tracts, while also ensuring other organs, such as the lungs, pancreas, liver and intestines, can fully function. Chloride also makes up part of salts, such as sodium chloride, which is found in sweat.6,7

Cilia: Cilia are hair-like projections within the body’s airways, which produce a sticky mucus that traps dust and other particles. The cilia beat rhythmically, removing the mucus and dirt out of the lungs, preventing irritation and infection of the lungs.8

Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene: The CFTR gene tells the body to produce CFTR proteins: channels that control the movement of salt and water in and out of cells in a number of organs, including the lungs.6,7 For more information on the CFTR gene, visit Causes of CF.

Enzymes: Substances that help break food into small nutrients that can be absorbed by the body, which are often produced in the pancreas.9

FEV1: Forced expiratory volume in one second (FEV1) measures the amount of air a person can exhale in one second.It is used to measure how well a person’s lungs are functioning.10

Genes: Genes are like an instruction manual for the body and carry the code that determines our physical characteristics (e.g. height, eye and hair colour) and much more. People have two copies of most genes: one copy from their father and one from their mother.11,12

Gene mutations: Sometimes, changes that occur in genes are called mutations or variants. Mutations may cause a gene to behave unexpectedly. This can result in a person having certain diseases, like CF.6,12,13

Genotype: The combination of genes you inherited from your parents.12

To read more about genes, gene mutations and genotype, visit Causes of CF.

Heel prick test: The heel prick test, also known as newborn blood spot test, involves taking a few drops of blood from a baby’s heel to find out if the baby has any of nine health conditions, including CF.14

Lung disease: People with CF may experience reduced lung function due to repeated infections and damaged airways. This leads to difficulty of clearing mucus from and moving air in/out of the lungs, which can cause a number of respiratory symptoms.15 To read more about how CF affects the lungs, visit Symptoms of CF.

Pancreas: Part of the digestive system and found just behind your stomach. It produces enzymes that help break down food and insulin that helps to keep the amount of glucose in the blood stable.9 To read more about how CF affects the digestive system, visit Symptoms of CF.

Pulmonary exacerbations: Periods of worsening respiratory symptoms that require antibiotic treatment and/or hospital admission.15

Sweat test: This test is often carried out in children to determine whether they have CF. A sweat test is used because people with CF have a higher amount of salt (chloride) in their sweat than people without CF. The test involves collecting sweat for 30 minutes. Usually, other tests (such as a blood test) may also be required to confirm a positive CF result.16

    1. CFTR2 2022. Clinical and Functional Translation of CFTR. Helpful Information about CF and CFTR2. Available at: Accessed January 2023.

    2. Greenberg J et al. Patient Prefer Adherence 2016; 10:2163–2169.

    3. Orenstein DM. Cystic Fibrosis: A Guide for Patient and Family. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2004.

    4. MacDonald K et al. Pediatr Drugs 2007;9(1):1–10.

    5. Orenstein DM. Ch.11: Genetics. Cystic Fibrosis: A Guide for Patient and Family. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2012.