Cystic fibrosis

Published by Bupa's Health Information Team, May 2011.

This factsheet is for people who have cystic fibrosis, or who would like information about it.

Cystic fibrosis affects around more than 8,500 people in the UK, making it one of the most common inherited conditions. Cystic fibrosis affects the surface of cells in many of the organs in the body, especially the lungs and digestive system, by clogging them up with thick, sticky mucus.

About cystic fibrosis

If you have healthy lungs, there is a layer of mucus in the walls of your airways. This mucus protects your lungs and removes bacteria out of your body. If you have cystic fibrosis, this mucus becomes excessively thick and sticky. This clogs up your airways, making it hard for you to breathe.

Cystic fibrosis also commonly affects the digestive system. Your pancreas makes enzymes that pass into your bowel to help break down the food that you eat. If you have cystic fibrosis, the duct that passes these enzymes from your pancreas into your bowel gets blocked by mucus, so food can’t be broken down properly.

Cystic fibrosis affects people differently. Around half of all people with cystic fibrosis can expect to live beyond the age of 38 and this is constantly increasing with improvements in treatment.

Symptoms of cystic fibrosis

One in 10 babies with cystic fibrosis get meconium ileus, which is when their bowels become blocked. This can be an early sign of cystic fibrosis. Meconium is a thick, black liquid passed out of the bowels in a baby’s first few days of life. If this meconium becomes too thick, it may block the bowels and make babies very ill. An operation to remove the blockage may be needed.

Lungs

If you have cystic fibrosis, the thick, sticky mucus is difficult to cough up and provides an ideal place for bacteria to grow. This can lead to chest infections. Over time, repeated chest infections can damage the lungs and make you prone to further chest infections. A troublesome cough, wheezing and breathlessness are common symptoms.

Digestive symptoms

If you have cystic fibrosis, enzymes made by your pancreas can’t reach your bowels because the passages are blocked by mucus. Without these enzymes, you may not be able to digest enough essential nutrients and you may find it difficult to gain weight. Malnutrition can lead to poor growth, physical weakness and delayed puberty in children. Your faeces may contain excess fat making them oily, smelly, large and difficult to flush away.

Symptoms of cystic fibrosis may differ in severity from person to person.

Complications of cystic fibrosis

There are many possible complications of cystic fibrosis, these may include:

• bronchiectasis (widening of the airways)
• cystic fibrosis-related diabetes – caused by chronic damage to your pancreas
• arthritis
• osteoporosis (thinning of your bones)
• fertility problems in men – the tube that carries sperm doesn’t develop properly or becomes blocked
• fertility problems in women – increased thickness of cervical mucus can reduce fertility
• nasal polyps (small growths in your nose)
• liver disease
• sinusitis
• diarrhoea
• constipation leading to bowel obstruction, known as distal intestinal obstruction syndrome (DIOS)
• gallstones
• pneumothorax (air leaks from your lungs into your chest cavity)

Causes of cystic fibrosis

Cystic fibrosis is an inherited condition that is caused by a faulty gene called the cystic fibrosis transmembrane conductance regulator. This faulty gene allows too much salt and not enough water into the cells of your body, causing the build-up of thick mucus.

You have to inherit the cystic fibrosis gene from both your mother and father to get the condition. If you inherit only one cystic fibrosis gene, you’re a carrier and you won’t have symptoms. However, you could pass the gene onto any children you have.

When both parents are carriers, with each pregnancy there is a:

• one in four chance of having a child with cystic fibrosis
• one in two chance of having a child who is a carrier of the cystic fibrosis gene
• one in four chance of having an unaffected child

Diagnosis of cystic fibrosis

Carrier screening

If you or your partner have a family history of cystic fibrosis, you can be tested before you start a family to see if you carry the cystic fibrosis gene. Cells are taken from the inside of your mouth and are sent to a laboratory for testing.

Antenatal screening

You can check if your unborn baby has cystic fibrosis from 10 weeks into your pregnancy.

Antenatal tests include the following.

• Amniocentesis – a sample of the amniotic fluid that surrounds your baby is tested.
• Chorionic villus sampling – a small sample of the placenta attached to your womb (uterus) is tested.

With both tests there is a risk of complications, including a small risk of miscarriage. You therefore may only be offered antenatal screenings if you’re at risk of having a child with cystic fibrosis, for example if you and your partner are both carriers of the cystic fibrosis gene or if you already have a child with cystic fibrosis. It’s important to speak to your GP if you’re thinking about antenatal screening.

Neonatal screening

Newborn babies in the UK are routinely screened for cystic fibrosis using blood spot screening. About five days after your baby is born, your midwife will prick your baby’s heel using a special device called a lancet. This collects a few drops of blood from your baby’s heel, which is then tested and can show if your baby has cystic fibrosis.

Sweat testing

If blood spot screening indicates that your baby may have cystic fibrosis or if your child has symptoms of cystic fibrosis, he or she may be offered a sweat test. This involves a small amount of sweat being collected from your baby’s skin and tested for its salt content. People with cystic fibrosis have a large amount of salt in their sweat, so measuring it can help to determine whether he or she has cystic fibrosis.

If the sweat test indicates that your child may have cystic fibrosis, he or she will be referred to a specialist cystic fibrosis team to discuss available treatments. The cystic fibrosis team includes a doctor, nurse, dietitian, physiotherapist (a health professional who specialises in maintaining and improving movement and mobility), psychologist and a social worker.

Genetic testing

If the sweat test provides a borderline result, your child may be offered a genetic test. A swab is rubbed gently against the inside of the cheek to take a saliva sample. This can usually be used to confirm if your child has cystic fibrosis or to find out if someone is a carrier of the cystic fibrosis gene.

Treatment of cystic fibrosis

Although there is a lot of research taking place to look at ways gene therapy or drug therapy can be used to target the cystic fibrosis gene, there is currently no cure for the condition. Many of these treatments are undergoing clinical trials and your cystic fibrosis team will update you if any are going on in your area.

Current treatment aims to:

• ease the symptoms of cystic fibrosis and make it easier to live with
• prevent worsening and long-term damage of cystic fibrosis
• minimise complications associated with cystic fibrosis

Self-help

Exercise

Physical activity is particularly important for people with cystic fibrosis. Keeping active helps to ease your symptoms, prevent deterioration of the lungs and improves muscular strength. You can try any sport or activity if you have cystic fibrosis. Talk to your nurse or physiotherapist about the best type of exercise for you.

Diet

If you have cystic fibrosis, it’s important to eat a high-energy diet. This means your diet should be high in calories as you won’t be able to digest all the food that you eat. This will also help you maintain a healthy weight and fight off infections. However, it’s important to follow your dietitian’s advice because suitable diets will vary from person to person.

Medicines

You may need to take enzyme replacements such as pancreatin (eg Creon or Pancrex) with snacks and meals. These replace the missing enzymes that can’t reach your bowel and allow you to properly digest the food that you eat. You may also need to take vitamin and mineral supplements. Speak to your cystic fibrosis doctor or pharmacist about the most suitable medicines for you.

You may also be given a range of medicines to treat cystic fibrosis. These may include:

• medicines that are usually used to treat asthma, such as bronchodilators, these are inhaled to help treat blocked airways and breathing problems caused by infections
  
• antibiotics to counter lung infections – these can be taken as tablets, inhaled into the lungs using a nebuliser (a device that makes a mist of water and medicine that you breathe in) or given by injection
  
• mucolytics, such as dornase alfa (Pulmozyme), to help break down thick, sticky mucus
  
• insulin, if you have diabetes, to help your body break down sugar

Always ask your cystic fibrosis doctor for advice and read the patient information leaflet that comes with your medicine.

Talking and physical treatments

Physiotherapy

If you have cystic fibrosis, you will need physiotherapy to help loosen the thick, sticky mucus from your lungs. This helps to prevent mucus blocking your air passages and so reduces infection and lung damage. There are different techniques that your physiotherapist may use. If your child has cystic fibrosis, your physiotherapist may teach you different techniques that you can do for your child.

Your muscles may become tight and weak around the chest and shoulders as a result of trying to cough up thick mucus. Therefore, your physiotherapist may encourage you to do regular stretching. This can help to mobilise the muscles and joints around your chest, back and shoulders and help to maintain a good posture.

Counselling

You may be offered counselling to help you cope with the emotional and psychological aspects of your illness or your child’s. Your cystic fibrosis team will usually include a psychologist.

If you have cystic fibrosis or if you’re a carrier of the cystic fibrosis gene, you may be worried about starting a family. Genetic counselling is a discussion with a person trained in genetics who will listen to your concerns. They can offer reassurance and support if you’re considering starting a family and want to understand any problems that may be involved.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.