Cystic Fibrosis

What is Cystic Fibrosis?

Cystic fibrosis is a genetic condition, which causes sticky mucus to build up in the lungs and digestive system.

Too much mucus in the lungs causes problems with breathing and repeated lung infections. Too much mucus in the digestive system can stop food being digested and absorbed properly, which mean children with cystic fibrosis can have problems with growth and putting on weight as a result. The NHS website gives an overview of cystic fibrosis here.

Who does Cystic Fibrosis affect?

People are born with cystic fibrosis, and it is usually diagnosed in younger children, but adults can also be diagnosed.

What are the symptoms?

Symptoms of cystic fibrosis may vary from child to child or person to person, but most commonly they include:

Cystic fibrosis is a progressive disease, which means it gets worse over time. The lungs may become damaged by repeated infections, and eventually the lungs might stop working properly.  

People with Cystic Fibrosis are also at risk of developing other related conditions, including Diabetes, weak bones (Osteoporosis)infertility in males, and liver problems.

How is Cystic Fibrosis caused?

Cystic fibrosis is a genetic condition. This means it is passed down through families. Cystic fibrosis is caused by a faulty gene called the Cystic Fibrosis Transmembrane Conductance Regulator or CFTR. CFTR controls the movement of salt and water in and out of cells and when it doesn’t work, thick sticky mucus builds up in the airway and digestive system.

How do genes work?

Genes provide instructions to the cells in our bodies so that they can make all the different proteins we need to function. We carry two copies of every gene in our cells: one from each of our two parents.

Sometimes genes can change or mutate, which means they are faulty. To have cystic fibrosis you must inherit two faulty copies of the CFTR gene, one from each parent. 

A person may be a “carrier” of the faulty gene, but if they only have one copy of the gene (and one good copy of the gene) they will not have cystic fibrosis, so may not know they have the faulty gene.

How is Cystic Fibrosis treated?

Cystic fibrosis cannot be cured, but there are a range of medicines and airway clearance techniques which can improve the symptoms of cystic fibrosis and treat the chest infections that are linked with the disease, including:

  • Airway clearance techniques (physiotherapy that helps to clear mucus that has built up in the lungs)- find out more on the Cystic Fibrosis Trust website and on the Airway Clearance web page.
  • Mucolytics (A group of medicines that make mucus less thick and easier to clear)
  • CFTR modulators- a group of medicines that try to correct the damaged CFTR, which is the root cause of cystic fibrosis
  • Antibiotics to treat chest infections
  • Bronchodilators, which are inhaled drugs that help to widen the airways and make breathing easier
  • Steroids to treat lung inflammation
  • Anti-fungals to treat fungal lung diseases
  • Lung transplant- if lung function is very poor, a transplant might be considered, however this is rare, particularly in children)
  • Treatment of other symptoms, e.g. bowel symptoms

Find out more about treatments for cystic fibrosis.

What can I do to help myself?

Taking all the prescribed medications exactly as prescribed and at the correct times, and be committed to airway clearance techniques. A good diet and exercise help everyone, including those with cystic fibrosis, to stay fit and active. Exercise can also help to shift a build-up of mucus in the lungs, and a physiotherapist can give advice on what exercise is right for you or your child. Some children may need extra nutritional support such as vitamin supplements or enzymes if the pancreas (one of the organs in the digestive system) isn’t working properly.

The Cystic Fibrosis Trust has more information on nutrition and eating well. You can also visit our Wellbeing web pages.

What should I do if I feel unwell?

Contact your local Cystic Fibrosis centre or your specialist healthcare provider. 24-hour NHS advice is available by dialling 111 or visiting

In an emergency dial 999 or go straight to your nearest accident and emergency department.


Cystic Fibrosis Overview- NHS website

Cystic Fibrosis- ASTHMA+LUNG UK

Cystic Fibrosis Trust

Cystic Fibrosis Kids

Cystic Fibrosis Care