Cystic fibrosis

What is cystic fibrosis?

Cystic fibrosis is a genetic condition that affects the body’s ability to control the movement of salt and water between cells.

This causes sticky mucus to build up in the lungs and digestive system. 

Sticky mucus in the lungs causes problems with breathing. People with cystic fibrosis are very vulnerable to lung infections. 

Mucus can also block parts of the digestive system, which can affect how food travels through the gut and how it’s broken down and absorbed. This means your child will struggle to digest and absorb nutrients from food. This can mean your child can have problems putting on weight and growing.

Boys with cystic fibrosis are usually infertile. This is because the tube that carries sperm from their testes to their penis is usually blocked or not there at all. But some men have been able to father children using IVF.

The condition does shorten life expectancy, but improved treatment and management is helping people with cystic fibrosis live longer. It’s thought that children born with cystic fibrosis nowadays are likely to live to an average age of over 50 years old. 

You can find more information and support from the Cystic Fibrosis Trust.

Last medically reviewed: September 2016. Due for review: September 2019

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.