What is cystic fibrosis?
Cystic fibrosis is a genetic condition in which the lungs and digestive system become clogged with thick sticky mucus.
Symptoms usually start in early childhood and include:
- persistent cough
- recurring chest and lung infections
- poor weight gain
Symptoms of cystic fibrosis usually become apparent in the first year of life.
An early sign is that an affected child’s sweat is unusually salty, which can be noticeable when you kiss your child.
Read more about the symptoms of cystic fibrosis.
Treating cystic fibrosis
There is no cure for cystic fibrosis. So the aim of treatment is to ease the symptoms and make the condition easier to live with. Treatment can also prevent or reduce long-term damage caused by infections and other complications.
Treatment options include:
- bronchodilators – which are a type of medication that helps expand the airways inside the lungs making it easier to breathe
- antibiotics – to treat chest and lung infections
- physiotherapy – there are a range of exercises that can help clear mucus from the lungs
In some cases a lung transplant may be required if the lungs become extensively damaged.
Read more about treating cystic fibrosis.
What causes cystic fibrosis?
Cystic fibrosis is caused by a genetic mutation; specifically a mutation in a gene called CFTR. A genetic mutation is when the instructions found in all living cells become scrambled in some way, meaning that one or more of the processes of the body do not work in the way they should.
The CFTR mutation allows too much salt and water into cells. This results in a build-up of thick, sticky mucus in the body's tubes and passageways. These blockages damage the lungs, digestive system and other organs, resulting in the symptoms of cystic fibrosis.
Read more about the causes of cystic fibrosis.
Who is affected
Cystic fibrosis is most common in white people of northern European descent.
The condition is much less common in other ethnic groups.
Babies are screened for cystic fibrosis at birth as part of the NHS newborn screening programme.
A small amount of the baby's blood is taken by a heel prick and transferred onto a card. The blood sample on the card is then analysed in the laboratory for cystic fibrosis and other inherited conditions, such as sickle cell anaemia.
Read more about screening for cystic fibrosis.
In previous years most children with cystic fibrosis would die of related complications before reaching adulthood.
The outlook has improved considerably in recent years due to advancements in treatment, although most people with cystic fibrosis will have a shorter than average life expectancy. However, this may well improve in the future.
A genetic disorder is a disorder caused by a fault in the genes. It is usually hereditary (runs in the family).
A carrier is a person or animal that spreads an organism that causes disease but does not become ill themselves.
When a child is born with cystic fibrosis, symptoms usually appear in the first year, although occasionally they develop later.
The thick sticky mucus in the body affects a number of organs, particularly the lungs and digestive system.
The symptoms and related problems of cystic fibrosis can vary in severity from person to person.
The main symptoms and problems are detailed below.
It is common for people with cystic fibrosis to have difficulties such as:
- persistent coughing and wheezing; the body tries to shift the thick mucus in the lungs by coughing it up
- recurring chest and lung infections; infections are caused by the continual build-up of mucus in the lungs, which provides an ideal breeding ground for bacteria
People with cystic fibrosis are vulnerable to harmful lung infections caused by certain strains of bacteria (these bacteria are rarely harmful to people without cystic fibrosis).
Two strains of bacteria that commonly infect people with cystic fibrosis are Pseudomonas aeruginosa and Staphlyococcus aureus. They multiply in the thick mucus inside the lungs and may cause serious health problems, such as repeated chest infections.
The danger is that a person with cystic fibrosis who has such an infection can easily pass it on to another person with cystic fibrosis through close personal contact or by coughing near them. This is known as cross-infection.
As more and more people with cystic fibrosis become infected with these bacteria, the bacteria may become resistant to antibiotic treatment, which is why cross-infection is such a problem.
There is a concern that people with cystic fibrosis are more likely to pick up strains from each other than from the environment. For this reason, it is recommended that people with cystic fibrosis do not come into close contact with each other.
Patients infected with these dangerous bacteria may be treated in separate clinics to those without the bacteria, to avoid cross-infection.
You can get more advice on cross-infection from the Cystic Fibrosis Trust website.
Cystic fibrosis can also cause mucus to block the ducts in the pancreas. The pancreas produces essential food-digesting enzymes. When it is blocked, not enough of the enzymes reach the intestines to help break down food, which can cause a number of troublesome symptoms. These are outlined below.
Large, smelly stools
If the digestive enzymes are not being produced, food is not adequately digested and excess fat is lost in the stools (‘poo’), making them bulky, oily, smelly and difficult to flush away.
Because the body cannot digest essential nutrients in food (particularly fat), it is often difficult to gain weight and infants may struggle to put on weight and grow. The medical term for not consuming sufficient nutrients is malnutrition.
Adults with cystic fibrosis often find it difficult to gain and maintain weight. In children with cystic fibrosis, this can result in delayed puberty if they are severely underweight.
In older people with cystic fibrosis, the pancreas can become more damaged. Diabetes can develop if the pancreas does not produce enough insulin, a hormone that controls the level of sugar in the blood.
Diabetes in people with cystic fibrosis is different from diabetes in people without cystic fibrosis. Usually, the symptoms of diabetes include feeling constantly thirsty, frequently needing to pass urine and feeling extremely tired.
This is less common in people with cystic fibrosis. Instead people with cystic fibrosis who develop diabetes may find it difficult to gain weight or may lose weight and see a decline in their lung function.
Cystic fibrosis-related diabetes is usually controlled by regular injections of insulin. Diabetes rarely occurs in children with cystic fibrosis.
Ears, nose and sinuses
People with cystic fibrosis can be prone to sinusitis (an infection of the cavities behind the cheekbones), which may need to be treated with nasal sprays or antibiotics.
Some older children and adults develop nasal polyps, which are fleshy swellings that grow from the lining of the nose or sinuses. If they become troublesome, they may need to be removed.
Bones and joints
Some older children with cystic fibrosis develop a form of arthritis (swelling and pain of the joints), usually in one or two large joints such as the knee. In most cases, symptoms improve with time and treatment.
Older children and adults may also be prone to thin bones, for many reasons, including repeated infection, poor growth or weight, lack of physical activity and lack of vitamins and minerals due to digestive problems.
People with cystic fibrosis are more at risk of developing osteoporosis if they are taking steroid medication (corticosteroids) to help with lung infections. Osteoporosis can cause joint pain and bones may fracture (break) more easily. Some people need to take drugs called bisphosphonates to help maintain their bone density.
Both men and women with cystic fibrosis can have problems conceiving children.
In virtually all men with cystic fibrosis, the tubes that carry sperm do not develop correctly, making them infertile.
Women with cystic fibrosis may find that their menstrual cycle becomes absent or irregular if they are underweight.
There is also an increased thickness of cervical mucus, which can sometimes reduce fertility.
However, some women with cystic fibrosis can have a successful pregnancy, though it may take longer than usual before conceiving a baby.
In a few people with cystic fibrosis, the tiny bile ducts in the liver can become blocked by mucus. This can be serious as the disease progresses, and in some cases it may be necessary to have a liver transplant.
People with cystic fibrosis, especially females, are more likely to have urinary incontinence (loss of bladder control) as urine can leak out of the bladder during coughing fits.
Enzyme Enzymes are proteins that speed up and control chemical reactions, such as digestion, in the body. Liver The liver is the largest organ in the body. Its main jobs are to secrete bile (to help digestion), detoxify the blood and change food into energy. Faeces Stool (also known as faeces) is the solid waste matter that is passed from the body as a bowel movement.
Cystic fibrosis is a genetic condition. It is caused by a faulty gene (known as the CFTR gene) that blocks the normal workings of a protein. This then allows too much salt and not enough water into cells.
This results in a build-up of thick, sticky mucus in the body's tubes and passageways. These blockages damage the lungs, digestive system and other organs, resulting in inflammation (swelling) and, in the lungs, repeated infections.
How the CFTR mutation is passed through families
Genes come in pairs. You inherit one set of genes from your mother and one set from your father.
To develop cystic fibrosis you would have to inherit the faulty gene from both your mother and your father.
In the UK, it is thought that 1 person in every 25 carries the faulty gene for cystic fibrosis, which is why it is a relatively common genetic condition. A carrier can be completely healthy and have no symptoms of cystic fibrosis.
If two carriers of the faulty gene have a baby, there is:
- a one-in-four chance that the child will not inherit either of the faulty genes (the child will not have cystic fibrosis and will not be a carrier of the condition)
- a one-in-two chance that the child will inherit one copy of the faulty gene from either their father or mother (the child will not have cystic fibrosis but will be a carrier of the condition)
- a one-in-four chance that the child will inherit both copies of the faulty gene (the child will have cystic fibrosis
Chromosome Chromosomes are the parts of a body cell that carry genes. A human cell usually has 23 pairs of chromosomes. Gene Genes contain information that you inherit from your parents, such as eye or hair colour. They are carried by chromosomes.
Most cases of cystic fibrosis in the UK are now identified through screening tests carried out early in life. However, some babies, children and even young adults are identified later following unexplained illness.
Diagnosing cystic fibrosis
There are three main ways of diagnosing cystic fibrosis:
- newborn testing
- antenatal testing
- sweat testing
A small amount of the baby's blood is taken by a heel prick and transferred onto a card. The blood sample on the card is then analysed in the laboratory for cystic fibrosis and other inherited conditions, such as sickle cell anaemia.
The sooner cystic fibrosis is diagnosed, the sooner treatment can begin and the better the outlook.
For more information on the newborn screening programme, see the UK Newborn Screening Programme Centre website.
A test can be done on a woman when she is pregnant to see if her unborn baby has cystic fibrosis. This can be carried out from 10 weeks of pregnancy.
The test uses chorionic villus sampling (CVS), where a fine needle is passed through the abdomen into the womb. Sometimes, a fine tube is passed through the vagina into the cervix (neck of the womb) instead. A tiny piece of the developing placenta, known as the chorionic tissue, is taken and the chromosomes in the cells of the tissue are examined for the faulty gene that causes cystic fibrosis.
Antenatal testing for cystic fibrosis is usually only offered to mothers who are thought to be at high risk of having a child with the disease, such as women with a family history of the condition.
If someone has cystic fibrosis, their sweat will have higher levels of salt than normal. A parent may first notice their child's symptoms of cystic fibrosis when they kiss them, as their skin can taste salty.
A sweat test measures the amount of salt in sweat. It is usually done by applying a very weak and painless electric current to a small area of skin to which a harmless chemical has been applied. This causes that area of skin to sweat. A sample of the sweat is then collected and analysed. If the salt content in the sweat is abnormally high, this confirms cystic fibrosis.
A sweat test may be carried out if:
- newborn screening tests are abnormal
- a child has symptoms of cystic fibrosis
- a child is born with a serious bowel obstruction known as meconium ileus
- a child or adult has symptoms suggestive of cystic fibrosis
A genetic test checks for the faulty cystic fibrosis gene by either analysing a saliva sample taken from inside the cheek using a swab or a blood sample. It can be useful to confirm cystic fibrosis if a sweat test gives a borderline result.
It can also be useful to find out which members of a family are carriers of the cystic fibrosis gene.
There is a simple test that uses a mouthwash to identify whether a person is a carrier of the cystic fibrosis gene.
Swishing the mouthwash collects a sample of cells from the mouth. This sample is then sent to a laboratory and the cells it contains are checked for the faulty cystic fibrosis gene.
It is important to have this test if the person’s partner is a known carrier, or if someone in the family has cystic fibrosis or knows that they carry it.
Testing in later life
Older children and adults may require regular testing to check how well (or not) their lungs and digestive system is working.
Tests that can be used for this purpose are described below.
You will be asked to breathe into a machine called a spirometer.
The spirometer takes two measurements: the volume of air you can breathe out in one second (called the forced expiratory volume in one second or FEV1) and the total amount of air you breathe out (called the forced vital capacity or FVC). You may also be given a type of breathing test known as a spirometry.
You may be asked to breathe out a few times to get a consistent reading.
The readings are compared with normal measurements for your age, which can show if your airways are obstructed.
A chest X-ray can be a useful method for assessing the state of your lungs
Computerised tomography (CT) scan
In a CT scan a series of X-rays are taken; these are then assembled by a computer into a more detailed ‘3D’ image of your lungs and digestive system.
Blood test During a blood test, a sample of blood is taken from a vein using a needle, so it can be examined in a laboratory. Chorionic villus sampling Chorionic villus sampling is a test during pregnancy to see if there are any genetic problems with the foetus. A small sample of tissue is taken from the placenta. Counselling Counselling is guided discussion with an independent, trained person to help you find your own answers to a problem or issue. Gene Genes contain information that you inherit from your parents, such as eye or hair colour. They are carried by chromosomes. Genetic Genetic is a term that refers to genes, the characteristics inherited from a parent. Lungs Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.
People with cystic fibrosis should be treated with help and advice from a team of healthcare professionals at a cystic fibrosis centre. With regular visits, the patient or parent can learn how to best manage the condition. As each case is different, they can receive tailored care for their or their child's condition.
There is no cure for cystic fibrosis. The aim of treatment is to ease the symptoms and make the condition easier to live with. It can also prevent or reduce long-term damage caused by infections and other complications.
Different types of treatment for cystic fibrosis are detailed below.
Medical treatments for cystic fibrosis help clear and control infections in the lungs and digestive system. They can also be used to treat some of the other health problems related to cystic fibrosis.
Bronchodilators are a type of medication that are inhaled to help the person breathe more easily. They are also used for asthma and relax the muscles that surround the airways in your lungs, helping them to open up.
Antibiotics are taken to fight infections in the lungs. They can be taken by mouth as pills, capsules or liquids, be inhaled through a nebuliser (a device that turns medication into a mist that can be breathed in), or they may be given intravenously (through a tube into a vein) if the infection is more severe.
All young children diagnosed with cystic fibrosis will be started on a course of antibiotics to protect them from certain bacteria, which will be continued for some years. For more advice on the use of antibiotics, see the Cystic Fibrosis Trust information on medication.
Steroid medication (corticosteroids) reduce the swelling of the airways, which can help with breathing in some patients. Steroid nasal drops and sprays can also be used to treat nasal polyps (small growths inside the nostrils).
Pulmozyme (DNase) is an enzyme, usually inhaled via a nebuliser, which helps to thin and break down the sticky mucus in the lungs so it is easier to cough up.
In most cases DNase will not cause any noticeable side effects
People who have diabetes as a result of their cystic fibrosis will need to take insulin and manage their diet to stabilise blood sugar levels. The dietary advice usually given to people with diabetes who do not have cystic fibrosis does not apply to most people with cystic fibrosis-related diabetes.
Bisphosphonates can be taken to treat osteoporosis (weak and brittle bones), which can occur as a result of cystic fibrosis. Bisphosphonates help maintain bone density and reduce risk of fractures.
Vaccinations and flu jabs
It is particularly important that people with cystic fibrosis are up to date with all the required vaccinations. People with cystic fibrosis should make sure they have an annual flu jab, as they are more susceptible to complications as a result of infection.
Digestive system, diet and nutrition
For people with cystic fibrosis, getting the right nutrition is vital. A healthy body weight is necessary to help fight off infections, and it is important there is enough reserve energy to rely on when the person is ill.
Cystic fibrosis causes mucus to build up and block the small channels that carry digestive juices and enzymes. Over time, this causes the pancreas to become damaged. The effect of cystic fibrosis on the pancreas varies from person to person, but most people have to take digestive enzymes from birth to help them digest food and get the nutrients they need, with every meal and snack. They also need to take vitamin supplements.
The diet of someone with cystic fibrosis should be high in calories, as they will not be able to digest all the food they eat.
A special diet should start as soon as cystic fibrosis is diagnosed, which will need to be adapted as people get older.
Babies with cystic fibrosis
Babies with cystic fibrosis may be breastfed as usual, otherwise most baby milks and formulas will be suitable. In some cases, if the baby is not gaining enough weight, a high-energy formula may be needed or nutritional supplements added to milk feeds to give the baby more calories (energy).
Ask a dietitian at the cystic fibrosis centre if you are unsure about this.
Before a baby moves onto solid foods, they may need extra salt as both breast milk and baby milk are very low in salt. Cystic fibrosis makes sweat much saltier and more salt than normal is lost through skin.
If the baby needs extra salt, the dietitian or doctor at the cystic fibrosis centre will advise on the appropriate amount and prescribe a salt solution.
Never add salt to a baby's food or drink without specific advice from cystic fibrosis specialists.
Babies can eat any normal solid baby foods, but they will need vitamin supplements to compensate for the loss of vitamins A, D, E and K in their stools.
These are available in two liquid preparations. Vitamins A and D are usually combined in one, and there is usually a separate one for vitamin E. Vitamin K is now prescribed by many doctors to older children.
A baby with cystic fibrosis will also need pancreatic enzymes to help them digest food. These take the place of the food-digesting enzymes missing from their digestive system. They usually come in the form of microspheres or minimicrospheres (granules), which can be mixed with a little formula, expressed breast milk or fruit puree and spoon fed ideally at the start, during and after the feed.
The granules should never be given dry as they can be a choking hazard. A dietitian can advise on the amount to use and the most suitable way to give the enzymes.
Children with cystic fibrosis
Children who have cystic fibrosis should eat a varied diet, with a large amount of protein and calories. Meals should include meat, fish and eggs, as well as starchy foods like bread and pasta. If a child's appetite is poor, give them food little and often, and offer snacks in between meals.
Children who find it particularly hard to gain weight can be given dietary supplements in the form of milk shakes or fruit juices. You can talk to a cystic fibrosis dietitian about these.
Like babies, children with cystic fibrosis will need to continue taking vitamin A, D, E and K supplements to compensate for the vitamins they lose.
Children also need to continue taking pancreatic enzymes with all fat-containing meals, snacks and drinks. The capsules should be taken before and during the meal and the number of capsules will vary depending on the fat content of the meal. Enzymes can be taken in easy-to-swallow capsules.
A dietitian may recommend salt supplements for a child with cystic fibrosis, especially in hot weather or if they are going on holiday to a country with a warm climate, where sweating may cause a loss of salt.
Children with cystic fibrosis are likely to eat more sugary foods than normal due to their high-calorie diet, so it is important to make sure they brush their teeth properly and visit the dentist regularly.
If a child cannot gain enough weight and dietary supplements have not helped, they may need to be tube fed.
This will usually be either nasogastric (the tube is inserted through the nose and goes down to the stomach), or gastrostomy (a small operation is carried out to insert the tube directly into the stomach). The other end of the tube is attached to a bag of high-calorie/nutrient food that is delivered straight to the stomach, usually while the child sleeps.
Adults with cystic fibrosis
Adults who have cystic fibrosis do not need to avoid any particular food, but it is important they have a diet high in protein and energy to maintain their weight. They should eat regular meals and snacks as this helps to maintain energy intake. They should eat three meals a day, including plenty of meat, fish and eggs, and eat several high-calorie snacks in between.
If someone with cystic fibrosis wants to be a vegetarian, they should talk to their dietitian about alternatives to meat. A vegan diet is not advised for people with cystic fibrosis as it tends to be especially low in energy.
Most adults with cystic fibrosis need to continue taking pancreatic enzymes with all fat-containing meals, snacks and drinks. The capsules should be taken before and occasionally during the meal and the number of capsules will vary depending on the fat content of the meal. There are different types and strengths so talking to the cystic fibrosis specialist team will help the person find one that suits them.
Creon is the usual preparation used in the UK. People with cystic fibrosis should not stop taking pancreatic enzymes unless they are told to do so by their dietitian or doctor, as this can lead to a serious blockage of the bowel.
Most adults need to continue taking vitamin A, D, E and K supplements. These come in the form of prescribed multivitamin tablets.
People with cystic fibrosis who lose a lot of weight due to an infection or illness may need to be tube fed to help them gain weight.
As in tube feeding for children, this will be either nasogastric or gastrostomy, depending on how long the tube must stay in for. A gastrostomy tube (which is inserted directly into the stomach) is best for longer periods of time or repeated courses of treatment as it is unlikely to be dislodged during coughing or physiotherapy.
The management of cystic fibrosis with physiotherapy differs for each person with the condition, and is specifically tailored to their needs.
Traditionally, physiotherapy for cystic fibrosis focused mainly on airway clearance (clearing mucus from the lungs). This still makes up a large part of daily treatment, but the role of the physiotherapist in cystic fibrosis has expanded to include daily exercise, inhalation therapy, posture awareness and, for some, the management of urinary incontinence.
It is beyond the scope of this article to discuss all of the airway clearway techniques available (your care team should be able to provide more information on airway clearway techniques).
The most widely used one in the UK is called active cycle of breathing techniques (ACBT).
Active cycle of breathing techniques (ACBT)
ACBT involve you repeating a cycle made up of a number of different steps. These are:
- a period of 20-30 seconds of normal relaxed breathing
- 3-4 deep breaths, where you hold each breath in for three seconds before breathing out
- ‘huffing’ – huffing involves taking a medium size breath in followed by a fast breath through your open mouth while using the muscles of your chest and stomach to help force the breath out – this should help push the mucus / up to a point where you can cough it out
- coughing – you should then cough every 2-3 huffs; but don’t try to force out sputum if it does not feel ready to be coughed out
You then repeat the cycle for 20-30 minutes.
(Do not attempt ACBT if you have not first been taught the steps by a suitably trained physiotherapist as performing the techniques incorrectly could damage your lungs).
If you are otherwise in good health you will probably only need to perform ACBT once or twice a day.
If you develop a lung infection you may need to perform ACBT on a more frequent basis.
Changing your position can also make it easier to remove mucus from your lungs. This is known as postural drainage.
Each technique can involve a number of complex steps but to summarise, most techniques involve you leaning or lying down while the physiotherapist or a carer uses their hands to vibrate certain sections of your lungs as you go through a series of ‘huffing’ and coughing.
There are also a number of devices that can help remove mucus from your lungs. These include:
- the flutter - a handheld device shaped like an asthma inhaler that delivers vibration to the airway of your lungs, making it easier to cough out mucus
- RC cornet - a device shaped like a small section of garden hosing which works in much the same way as the flutter
- the Acapella - a device shaped like a small torch that uses a combination of vibration and air pressure to help remove mucus
Your PCT does not have any obligation to pay for these devices so possibly you would have to pay if you wanted one.
These type of devices cost in the region of around £45-60.
Some techniques use large pieces of equipment, which can be very expensive and are usually only available for use in a hospital, such as a high frequency chest wall oscillation (HFCWO). This involves using an electric air compressor that connects to an inflatable jacket (vest) to vibrate the chest
Exercise is recommended for everyone with cystic fibrosis. This may vary from taking part in normal school activities to individualised exercise programmes. Infants and toddlers with cystic fibrosis should have some exercise included in their normal daily routine.
Any sport or exercise that gets a person with cystic fibrosis moving is good, but if there are any concerns or worries, they should ask their physiotherapist.
Children and adults are also encouraged to include stretching exercises into their routine to mobilise the joints and muscles around their chest, back and shoulders, and to be aware of maintaining good posture.
In severe cases of cystic fibrosis, when the lungs stop working properly and all medical treatments have failed to help, a lung transplant may be recommended.
Both lungs need to be transplanted as they will both be affected by the condition. A lung transplant is a serious operation that carries certain risks, but it can greatly improve the length and quality of life for people with severe cystic fibrosis.
The British Transplantation Society estimated that on average around 9 out of 10 people will survive for at least a year after a transplant and 5 out of 10 will survive for at least five years (there have been reports of people living for 20 years or more after a transplant).
The outlook for people with cystic fibrosis is often better than average for transplant patients as they are often younger and in better health than other transplant candidates.
Read more about lung transplants.
Antibiotics Antibiotics are medicines that can be used to treat infections caused by micro-organisms, usually bacteria or fungi. Examples of antibiotics include amoxicillin, streptomycin and erythromycin. Bronchodilator Bronchodilator medicines are used to widen the airways of the lungs to help with breathing difficulties. An example is salbutamol. Enzyme Enzymes are proteins that speed up and control chemical reactions, such as digestion, in the body. Gene Genes contain information that you inherit from your parents, such as eye or hair colour. They are carried by chromosomes. Heart The heart is a muscular organ that pumps blood around the body. Inflammation Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area. Lungs Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen. Physiotherapy Physiotherapy is a treatment that uses physical movements, massage and exercise to relieve illness or injury.