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Cystic Fibrosis (CF)

A common hereditary disease in which exocrine (secretory) glands produce abnormally thick mucus. This mucus can cause problems in digestion, breathing, and body cooling.

PubMed Health Glossary
(Source: NIH - National Cancer Institute)

Cystic Fibrosis

Cystic fibrosis (SIS-tik fi-BRO-sis), or CF, is an inherited disease of the secretory (see-KREH-tor-ee) glands. Secretory glands include glands that make mucus and sweat.

"Inherited" means the disease is passed from parents to children through genes. People who have CF inherit two faulty genes for the disease - one from each parent. The parents likely don't have the disease themselves.

CF mainly affects the lungs, pancreas, liver, intestines, sinuses, and sex organs.


Mucus is a substance made by tissues that line some organs and body cavities, such as the lungs and nose. Normally, mucus is a slippery, watery substance. It keeps the linings of certain organs moist and prevents them from drying out or getting infected.

If you have CF, your mucus becomes thick and sticky. It builds up in your lungs and blocks your airways. (Airways are tubes that carry air in and out of your lungs.)

The... Read more about Cystic Fibrosis

What works? Research summarized

Evidence reviews

[The effects of physical exercise on cystic fibrosis: a review of the literature]

Bibliographic details: Schaar B, Platen P.  [The effects of physical exercise on cystic fibrosis: a review of the literature]. [Literaturanalyse: sportliche Activitaten bei zystischer Fibrose.] Atemwegs und Lungenkrankheiten 2006; 32(9): 361-365

Enteral tube feeding for cystic fibrosis

Bibliographic details: Malt G.  Enteral tube feeding for cystic fibrosis. International Journal of Child and Adolescent Health 2011; 4(1): 111-112 Available from: https://www.novapublishers.com/catalog/product_info.php?products_id=21072

Low glycaemic index dietary interventions in youth with cystic fibrosis: a systematic review and discussion of the clinical implications

A systematic review was conducted to assess what is known about the effect of low glycaemic index (GI) diets on glycaemic control, weight and quality of life in youth with cystic fibrosis (CF). Eligibility criteria were systematic reviews, randomised and non-randomised trials of low GI dietary interventions in CF. Outcomes examined were glycaemic control, quality of life, anthropometry and respiratory function. Reference lists were manually searched and experts in the field were consulted. Four studies met the eligibility criteria; two were excluded because they did not include data on any of the outcomes. The remaining two were studies that examined GI secondary to any other intervention: one used GI as a factor in enteral feeds and the other incorporated low GI dietary education into its treatment methodology. There is insufficient evidence to recommend use of low GI diets in CF. Since there is evidence to support use of low GI diets in type 1, type 2 and gestational diabetes, low GI diets should be tested as an intervention for CF. The potential risks and benefits of a low GI diet in CF are discussed.

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Summaries for consumers

Human Growth Hormone for Children With Cystic Fibrosis: A Review of the Research for Parents and Caregivers

This guide is for anyone who takes care of a child or teen with cystic fibrosis (CF) and helps make decisions about treatment. You may have heard about using human growth hormone (HGH) for children with CF and want to know more about the research.

Vaccines for preventing infection with Pseudomonas aeruginosa in cystic fibrosis

Cystic fibrosis is a hereditary disease where thick mucus is produced in the lungs. Pseudomonas aeruginosa and other bacteria cause long‐lasting lung infections which result in permanent lung damage. Vaccines aimed at reducing infection with Pseudomonas aeruginosa have been developed, and it is important to know whether vaccination can prevent lung infection. We searched for randomised controlled trials and included three trials with 483, 476 and 37 patients respectively. No data are available from one of the large trials, which is unpublished. In the other large trial and in the small trial, the risk of getting a chronic infection was not decreased. In the large trial, one patient was reported to have died in the observation period. In that trial, 227 adverse events (four severe) were registered in the vaccine group and 91 (one severe) in the control group. We cannot recommend the use of vaccines against Pseudomonas aeruginosa.

Elective (regular) versus symptomatic intravenous antibiotic therapy for cystic fibrosis

Chronic infection of the airways by Pseudomonas aeruginosa in people with cystic fibrosis is associated with deterioration in respiratory function. Intravenous antibiotics are the standard therapy for pulmonary exacerbations caused by this micro‐organism. Many centres advocate the use of elective (regular) three‐monthly antibiotics to reduce the frequency of exacerbations and therefore slow the deterioration of lung function. Alternatively, intravenous antibiotics are only prescribed when symptoms indicate. Elective therapy may encourage multi‐resistance to antibiotics. This review aimed to identify randomised and quasi‐randomised controlled trials that evaluated the results of the two different approaches. No clear conclusions were identified. This review will no longer be regularly updated. Searches will still be undertaken on a two‐yearly basis by the Cochrane Cystic Fibrosis & Genetic Disorders Group. If, in future, relevant trials are identified, the review will be updated again.

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Terms to know

Body Fiber
In the body, fiber refers to tissue made of long threadlike cells, such as muscle fiber or nerve fiber.
Exocrine Glands
An organ that makes one or more substances, such as sweat, tears, saliva, or milk. Exocrine glands release the substances into a duct or opening to the inside or outside of the body.
Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue. Fibrosis is similar to the process of scarring.
Inherited; having to do with information that is passed from parents to offspring through genes in sperm and egg cells.
A group of cells that secrete substances. Endocrine glands secrete hormones. Exocrine glands secrete salt, enzymes, and water.
A thick, slippery fluid made by the membranes that line certain organs of the body, including the nose, mouth, throat, and vagina.
Respiratory System
The organs that are involved in breathing. These include the nose, throat, larynx, trachea, bronchi, and lungs. Also called respiratory tract.
To form and release a substance. In the body, cells secrete substances, such as sweat that cools the body or hormones that act in other parts of the body.
Fluid that exits the body through pores in the skin usually due to physical stress and/or high temperature for the purpose of regulating body temperature and removing certain compounds from the circulation.

More about Cystic Fibrosis

Photo of a child

Also called: Mucoviscidosis, Fibrocystic disease

Other terms to know: See all 9
Body Fiber, Exocrine Glands, Fibrosis

Keep up with systematic reviews on Cystic Fibrosis:


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