What is cystic fibrosis (CF)?
Cystic fibrosis is a life-limiting, inherited condition caused by a faulty gene that disrupts the movement of salt and water in the body’s cells, causing the mucus that naturally occurs in the body to be thicker and stickier than in people without cystic fibrosis. This sticky mucus causes problems, particularly in the lungs and digestive system, but can also affect other parts of the body.
How do you get cystic fibrosis?
You can’t catch cystic fibrosis, or develop it later in life. For someone to have CF, they must inherit two copies of the faulty gene – one from each of their parents. If both parents have the gene, then there is a 25% chance their child will have cystic fibrosis. The faulty gene is carried by 1 in 25 people. A carrier does not have cystic fibrosis, they just carry one copy of the faulty gene that causes it.
If Stephanie is a CF carrier but the father is not, then there is a one in two chance the baby will carry the CF gene, but they will not have cystic fibrosis.

Carrier testing
A blood test can determine if a person is a carrier of the faulty gene that causes cystic fibrosis. This is important if your partner is a known carrier, or if a relative has cystic fibrosis or is a known carrier. You can request carrier testing by speaking to your GP. Find out more in the Trust's Carrier Testing factsheet (PDF).
Since 2007, CF has been one of the conditions that all newborns in the UK are screened for as part of the heel prick test, which is carried out shortly after birth. This allows for much earlier diagnosis and treatment by specialist CF teams.
Find out more about the NHS Newborn Screening programme.
How CF is treated?
Along with their regular GP, people with CF are treated by multidisciplinary teams of specialist CF professionals, including doctors, nurses, physiotherapists and dietitians. Paediatric teams look after children from diagnosis through to teenage years when they are ready to move onto their adult CF team.