What is Cystic Fibrosis?

Cystic fibrosis is an inherited (genetic) condition that affects more than 10,000 people in the UK. You are born with CF and cannot catch it later in life (although some people may not find out until they are older that they have it).

The main symptoms are due to a build up of sticky mucus - this can cause problems in the lungs, digestive system and other organs.

Symptoms can vary quite widely from person to person.

How is Cystic Fibrosis Diagnosed?

CF can be diagnosed at any age.

Diagnosis may involve a blood test, a swab taken from the inside of your cheek, or a sweat test.

Since 2003 babies born in Scotland have been offered a screening test shortly after birth - this involves taking a small sample of blood from a baby's heel. If this screen is positive follow up testing is offered to determine if the baby has CF. Many people with CF are now being diagnosed through this process.

If you were born before 2003 you may have been diagnosed after being unwell either as a child or an adult.

Sometimes people find out they have CF after seeing a doctor for seemingly unrelated problems (such as fertility issues, sinus conditions or bowel problems).

You may have been tested for CF because a relative had been diagnosed CF and you were told you might be affected too.

Blood Tests

Cheek swab

Sweat Test

Blood Tests

Blood tests can be taken to look for the faulty CF gene. This test can tell you if you have cystic fibrosis or if you are a carrier of the CF gene.

Cheek Swab Test

Cheek swabs involve scraping a small number of cells from the inside of your cheek. These cells are then tested (in a similar way to the blood test) if you are affected by CF or if you are a carrier of the CF gene.

Sweat Test

A sweat test measures the amount of salt (sodium and chloride) in skin sweat. People with cystic fibrosis may have an unusually high salt level in sweat.

I have been told I am a CF carrier. What does that mean?

1 in 25 people in the UK will be a carrier of the faulty CF gene - most of these people will not know they are a carrier (they do not have cystic fibrosis and so do not have any symptoms).

CF carriers have one faulty copy of the gene and one unaffected copy.

They are able to pass on the faulty gene to their children - if two carriers have children together there is a chance their children may have cystic fibrosis.

Image courtesy of the CF Trust

If both parents are CF carriers there is a 1 in 4 chance that if they have a child he or she will have CF. There is also a 1 in 2 chance that the child will be a carrier (but will not have CF), and a 1 in 4 chance that the child will not carry any copy of the faulty gene at all.

If you are a CF carrier and are considering having children you may wish to discuss this with your GP - they may refer you and your partner on to your local genetics team for further advice and support.