What is cystic fibrosis?

Cystic fibrosis (CF) is a serious genetic condition in which cells in certain parts of the body produce too much mucus.

It mainly affects the lungs and the pancreas but can also affect other parts of the body, including the liver, reproductive organs, sweat glands, nose and sinuses.

Around 10,400 people in the UK have cystic fibrosis; that’s 1 in every 2,500 babies born. Cystic fibrosis affects around 100,000 people in the world (source: CF Trust, accessed Jan 2019).


Cystic fibrosis Symptoms

Symptoms of CF usually start in early childhood. The main symptoms include:

  • a persistent cough
  • wheezing and breathlessness
  • recurring chest and lung infections
  • poor weight gain and large, smelly stools (caused when ducts in the pancreas become blocked)
  • bladder incontinence

People with CF may go onto develop conditions such as diabetes and problems with their liver (as ducts in their liver become blocked). They may also suffer from sinusitis, arthritis and infertility.

What causes cystic fibrosis?

Cystic fibrosis is caused by a mutation of the CTFR genes. These genes are responsible for making a protein that controls the flow of salt and water in and out of the body’s cells. When these genes have mutated, they allow too much salt and water into the cells, resulting in thick, sticky mucus which blocks the body’s tubes and passageways.

Cystic fibrosis is an inherited condition, whereby the affected individual inherits two faulty genes – one from each parent. Children with one normal CTFR gene, and one faulty gene are known as ‘CF carriers’. Although they will not normally experience any symptoms, they can pass the mutated gene onto their children.

Diagnosing cystic fibrosis

Cystic fibrosis can be diagnosed via the following tests:

Sweat test

People with cystic fibrosis typically have high levels of salt in their sweat. Many parents notice this symptom in their child as their skin tastes salty when they kiss them. This test detects the levels of salt in skin sweat.

Genetic test

In genetic testing, cells are scraped from inside the cheek or captured during a blood test to detect the CTFR gene.

Screening for cystic fibrosis

Screening of newborn babies in the UK is available on the NHS. A small heel prick blood test is taken to detect a chemical called immunoreactive trypsinogen, which is typically high in children with cystic fibrosis.

Tests are also available to determine if you are a carrier or if your unborn child has cystic fibrosis. These tests are usually only offered to individuals whose partners are carriers, or with a family history of cystic fibrosis.

Cystic fibrosis treatment

Since there is no cure for cystic fibrosis, the aim of treatment is to make life more manageable and to prevent any unnecessary complications. Treatment can involve:


A range of medications, from antibiotics to flu jabs and steroids, can help to prevent and control infections in the lungs and digestive system.

Diet and nutrition

Since individuals with CF often find it hard to digest their food, a diet high in calories supplemented with digestive enzymes will aid digestion and help prevent weight loss.

Physiotherapy and exercise

Programmes of physiotherapy and exercise usually include airway clearance (clearing mucus from the lungs), inhalation therapy, posture awareness, and management of urinary incontinence.

Airway clearance
Breathing techniques and devices are provided to patients to help remove mucus from their lungs.


In severe cases where the lungs have stopped working and responding to treatment, a lung transplant may be recommended. Although a serious operation, a lung transplant can greatly improve quality and length of life.

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