Cystic Fibrosis : Symptoms, Causes & Treatment

Cystic fibrosis is an inherited metabolic disease. In those affected, body fluids such as saliva, bronchial mucus or pancreatic secretions are much more viscous than usual. This causes breathing problems and indigestion, among other things. Cystic fibrosis is not curable. With consistent therapy, however, the course of the disease can be slowed down. Read here what symptoms cystic fibrosis causes and how to treat it.

ICD codes for this disease: E84

Cystic fibrosis: A brief overview

  • Description: Hereditary metabolic disease, causes thick mucus to form in the lungs and other organs.
  • Symptoms: Respiratory problems, dry cough, susceptibility to lung infections, failure to thrive, indigestion, severe diarrhea, fatty liver, reduced fertility.
  • Causes: Inheritance of defective genes that affect the consistency of body fluids. Outbreak of the disease only if both parents pass on a diseased gene to the child (autosomal recessive inheritance).
  • Diagnostics: Blood test for immunoreactive trypsin (IRT), pancreatitis-associated protein (PAP), sweat test, genetic test.
  • Treatment: Mucolytics, bronchodilators, inhalation, antibiotics for bacterial respiratory infections, cortisone, CFTR modulators, lung transplantation.
  • Prognosis: Not curable, course depends heavily on the severity and time of diagnosis, shortened life expectancy.

Cystic fibrosis: Description

Cystic fibrosis is an inherited metabolic disease. The formation of various body fluids is disturbed. The secretions of the lungs, pancreas and other organs are more viscous than in healthy people.

cystic fibrosis

Thick slime

The viscous mucus clogs, among other things, the small branches of the bronchi and the ducts of the internal organs. Respiration and digestion are particularly badly affected. As the disease progresses, the organs become less and less able to function.

Errors in the genome

The disease is caused by errors in the genetic material. Cystic fibrosis is therefore not curable. Time of diagnosis and severity of symptoms can vary greatly between individuals. In many children, cystic fibrosis is massively noticeable from birth, in other cases it is only recognized later.

Signs and symptoms of cystic fibrosis

Cystic fibrosis symptoms can vary greatly from patient to patient. The disease affects the functioning of various organs, but primarily the lungs and digestive system.

Recognize early signs

When the first symptoms appear with cystic fibrosis varies from person to person. In most cases, symptoms of cystic fibrosis appear within the first year of life. In this way, the disease can usually be diagnosed early and treatment can be started quickly.

However, some patients do not have significant symptoms until they are young. Not everyone affected shows the full range of possible symptoms. The severity of the symptoms also varies.

Altered body fluids

In cystic fibrosis, the formation of the so-called chloride ion channels in the cell membranes is disrupted. This changes the composition of body fluids. The easiest way to determine this change is in the sweat of those affected. Their sweat contains more salt than healthy people.

The salts sodium and chloride, which belong to the so-called electrolytes, are enriched in their sweat. Mucoviscidosis sufferers therefore lose more body salts through sweating.

Diverse cystic fibrosis symptoms

The disease affects a wide range of organ systems. The first symptoms of cystic fibrosis often appear in the lungs and digestive tract. Other symptoms can arise over the course of life. The symptoms can be treated well with targeted therapy.

However, the symptoms can also take on threatening proportions. It is particularly dangerous when the bronchi become clogged with viscous mucus. In extreme cases, patients can then suffocate.

Cystic fibrosis: lung symptoms

  • Breathing problems and dry cough

In most cases, pulmonary symptoms of cystic fibrosis only appear in slightly older infants. Newborns usually have no breathing problems. In slightly older children, cystic fibrosis symptoms often manifest themselves in the form of a chronic, dry cough that is similar to whooping cough.

The mucus in her airways is increased, tough and viscous. This impedes the flow of air in the lungs. Over time, progressive shortness of breath develops.

  • Frequent infections

The increased mucus production in the lungs makes it easier for bacteria to colonize and cause an infection. Recurrent pneumonia are mainly caused by bacteria such as staphylococci and Pseudomonas species.

The disturbed salt balance in the lungs also impedes the body’s own defences. Bleeding in the lungs can also occur. A typical sign of this is coughing up phlegm mixed with blood.

Although the lungs are damaged from an early age, the first symptoms of cystic fibrosis in the respiratory tract often do not appear until primary school age or even later.

The symptoms are sometimes only noticeable when large parts of the lung tissue have already been destroyed or the airways are severely narrowed.

Cystic Fibrosis: Symptoms of the Pancreas

In patients with cystic fibrosis, the pancreas often becomes inflamed: it secretes a secretion that contains enzymes, among other things for fat and carbohydrate digestion. In people with cystic fibrosis, the secretion builds up due to its viscosity and causes inflammation of the pancreas.

As the disease progresses, the pancreatic tissue hardens and scars. Doctors speak of fibrosis. The fibrosis gradually destroys the pancreas.

In addition to its digestive secretion, the pancreas also produces the hormone insulin in special cells – the beta cells . Among other things, it is necessary for the sugar utilization in the body.

In cystic fibrosis patients, the viscous digestive secretion in the ducts of the pancreas also gradually destroys the beta cells – insulin production is impaired and insulin deficiency develops (especially in patients over the age of 10). As a result, a type of diabetes can develop: type 3 diabetes.

Cystic fibrosis: Symptoms of the bile

The pancreas and gallbladder share a common duct into the intestine. Therefore, the back-up of pancreatic secretions can also cause inflammation of the gallbladder. Gallstones often form and can completely block the flow of bile from the gallbladder.

Cystic fibrosis: digestive tract symptoms

In addition to lung problems, cystic fibrosis very often causes symptoms in the digestive tract. Fat digestion, for example, is impaired by the lack of bile. This is why the patients often do not tolerate greasy food well. Most of the food eaten is excreted undigested. Very bulky and soft stools are typical.

  • Diarrhea and stunted growth

Affected children, including infants, often suffer from severe diarrhea. Although they drink and eat enough, they hardly gain weight. Growth disorders and malnutrition are therefore other classic consequences of the disease.

Such digestive problems can also occur with many other diseases. Only in combination with breathing problems are they an indication of cystic fibrosis, which should definitely be investigated.

  • Anal prolapse

As it progresses, cystic fibrosis can lead to various complications in the digestive tract. The most common is a so-called anal prolapse. A part of the anus mucosa bulges out of the anus. Such an incident must be operated on as soon as possible.

  • Intestinal obstruction

Invagination of the bowel or bowel obstruction also occur frequently. Both complications are associated with severe abdominal pain and significant digestive problems.

The pain usually occurs in episodes, especially after eating. An intestinal obstruction is fatal if left untreated. Cramp-like, acute abdominal pain should therefore always be clarified by a doctor.

Cystic fibrosis: Liver symptoms

  • Fatty liver

The liver also suffers from the backlog of bile. Fatty liver develops in many patients during the course of the disease. This can be accompanied by fatigue, loss of appetite, a feeling of fullness and flatulence and, in rare cases, a feeling of pressure or slight pain in the upper abdomen.

  • Shriveled liver

In rare cases, cystic fibrosis patients develop a liver cirrhosis. This severe dysfunction of the liver is first noticeable in the form of jaundice. Yellowing of the whites of the eyes is a sign of jaundice.

After a longer period of time, heart problems also appear and the performance of those affected continues to decrease.

Cystic Fibrosis: Decreased fertility

More than half of all male cystic fibrosis patients are infertile. In most cases, those affected produce fertile sperm in their testicles. However, these cannot get through the vas deferens because they are clogged with viscous mucus.

Women with cystic fibrosis are usually less fertile. In principle, they can conceive and carry a child. However, viscous mucus accumulates in their fallopian tubes, which sperm find difficult to penetrate. The probability of pregnancy decreases rapidly, especially with increasing age.

Cystic fibrosis: Symptoms in children

cystic fibrosis

Cystic fibrosis is a genetic disease. It is therefore always present from birth. But the classic cystic fibrosis symptoms do not always appear in childhood.

However, there are often unspecific clues that should be followed up. This is especially true if cases of cystic fibrosis have already occurred in the family.

Cystic fibrosis: Symptoms in the digestive tract

An indication of a metabolic disorder is, for example, a bloated stomach over a long period of time. Children often suffer from diarrhea. In newborns, a severely delayed first bowel movement can also be an indication of cystic fibrosis.

In many cases, failure to thrive and grow occurs even though children eat ravenously. Only in rare cases does constipation occur as a result of the disease.

Respiratory symptoms

Other symptoms that can indicate cystic fibrosis are rattling breathing and severe restlessness. Many children suffer from chronic inflammation of the paranasal sinuses.

This is particularly noticeable through pain in the face that cannot be precisely localized. Nasal polyps are also more common in children with cystic fibrosis than in healthy children.

If children suffer from breathing problems or digestive disorders for a longer period of time, it is always advisable to consult a doctor as a precaution. Life-threatening situations can quickly arise in children because they cannot articulate their symptoms themselves or assess their severity.

Cystic fibrosis: Causes and risk factors

Cystic fibrosis is caused by a genetic defect. The pathological change is on the seventh chromosome in the so-called CFTR gene.

The CFTR gene (cystic fibrosis transmembrane regulator gene) contains the blueprint for a channel in the cell membrane through which chloride ions enter the cell. In cystic fibrosis patients, the defective chloride ion channels block salt transport into certain body cells.

The affected gland cells then secrete viscous mucus instead of the otherwise liquid secretion. In the lungs, paranasal sinuses, pancreas, intestines, bile ducts and gonads, viscous mucus secretions with a high salt content form.

Cystic fibrosis: How at risk is my child?

Cystic fibrosis only breaks out when both parents inherit a pathologically altered CFTR gene in their child. These parents are usually both healthy themselves – they have a healthy and a defective CFTR gene.

People with cystic fibrosis are only partially fertile. However, some patients become parents. However, diseased fathers or mothers always pass on a diseased gene, since both CFTR genes carry the CF information. However, their children only become ill if they also inherit a diseased gene from the other parent.

Couples with a family history of cystic fibrosis should seek genetic counseling before planning a pregnancy.

Preimplantation diagnosis

Parents who could inherit cystic fibrosis to their child can take advantage of pre-implantation diagnostics. The egg cells are first artificially fertilized. The first cell divisions take place in the test tube.

Before the embryo created in this way is inserted into the woman’s uterus, it is checked for altered gene characteristics. Only embryos that do not carry the diseased gene are then implanted.

Regardless of this, it can also be examined during pregnancy whether the child will later develop cystic fibrosis.

How cystic fibrosis is diagnosed?

Unlike a few years ago, newborn screening is now routine in most hospitals. It includes, among other things, an examination for cystic fibrosis. Participation in this screening procedure is voluntary and requires the consent of the newborn’s parents.

Screening in blood and sweat

Blood is drawn from the newborn for screening. The test for cystic fibrosis includes several stages:

  • Blood test : Test for elevated levels of Immunoreactive Trypsin (IRT) and Pancreatitis Associated Protein (PAP). If there are any abnormalities, the sweat test is carried out.
  • Sweat test : Sweat test for cystic fibrosis, People with cystic fibrosis have a significantly higher salt content in their sweat than healthy people. For the cystic fibrosis sweat test, the content of the salts sodium and chloride in body sweat is measured. In children, the sweat is collected on the forearm and then analyzed. If there is a suspicion, a genetic test is carried out.
cystic fibrosis

Genetic test

In patients with cystic fibrosis, the so-called CFTR gene is modified, which provides the building instructions for specific ion channels. This construction manual is long, it consists of around 6500 base pairs.

An error can creep into the code anywhere – cystic fibrosis can therefore be based on various genetic changes. These have different effects. Therefore, only the most important deviations in the CFTR gene are tested.

If both CFTR genes, i.e. that from the father and that from the mother, have a mutation, this – together with the positive sweat test – confirms the diagnosis of cystic fibrosis.

Family history provides clues

If no appropriate newborn screening has been carried out and the suspicion of cystic fibrosis only arises later, the family doctor or an internist is the right contact person. In a first conversation, he records the medical history.

If cystic fibrosis is suspected, the main focus is on the family history (is there a known history of cystic fibrosis in the family? Is one of the parents a known carrier of a defective CFTR gene?).


A physical examination will then take place. The doctor listens to the patient’s lungs and feels his internal organs. He can already rule out some other diseases that are associated with symptoms similar to those of cystic fibrosis.

Sweat test and genetic test, as described above, also help if there is a suspicion of cystic fibrosis in older children, adolescents or adults.

Once the diagnosis has been made, the doctor can use various examinations to check the extent to which the function of the internal organs is impaired and whether complications or secondary diseases are already emerging. Such examinations are sometimes also carried out routinely to monitor the progression of cystic fibrosis.

For example, blood tests can be used to determine whether the insulin secretion from the pancreas is reduced and the blood sugar level is elevated – warning signs of diabetes. Liver function values and the concentration of fat-soluble vitamins can also be measured in the blood.

The concentration of the digestive enzyme elastase (derived from the pancreas) and the fat concentration are determined in stool samples.

Tissue samples from the patient’s throat or sputum are examined in the laboratory for bacterial infections.

Imaging methods (such as X-rays, computed tomography = CT) are also often revealing. They can be used, for example, to detect lung infections. Nasal polyps can also be detected by CT.

Measurements of lung function (lung function tests) show how well the lungs are working.

Testing family members

If cystic fibrosis is diagnosed in a family, it makes sense that all other family members also undergo an examination. Mild forms of cystic fibrosis can also occur.

Then it often takes many years before the cystic fibrosis becomes noticeable with clear symptoms. Nevertheless, early diagnosis and cystic fibrosis therapy are also important for those affected in order to increase life expectancy.

Cystic fibrosis treatment

Cystic fibrosis is not curable. Children born with cystic fibrosis suffer from the effects of the disease throughout their lives. Using a combination of physiotherapy, medication and inhalation, however, the course of the disease can be significantly slowed down. The goal of cystic fibrosis therapy is primarily to enable those affected to live as normal a life as possible.

Learning to live with the disease

It is particularly important for children to learn how to deal with the disease in the long term. Children with cystic fibrosis should learn as early as possible what the disease means and how it affects the body. A stay in hospital with special training units can be useful for this.

Children and parents learn how they should eat, what sport is like and how best to behave in critical situations. Parents and children are also informed about hygiene measures (according to the recommendations of the Robert Koch Institute): regular and extensive hand hygiene (hand washing with soap and water), no upholstered furniture and potted plants.

Help for the lungs

There are various options for treating the symptoms of cystic fibrosis. Which of these make sense in individual cases depends on the age of the patient and the severity of the symptoms.


Lung problems plague cystic fibrosis patients the most. Regular inhalation with special additives (mucolytics) loosens the tough mucus and makes it easier to cough it up.


So-called beta-2 sympathomimetics widen the bronchi, which makes breathing even easier.

Medicines for respiratory infections

Poor ventilation of the lungs makes people with cystic fibrosis more susceptible to bacterial respiratory infections. Those affected should be treated with antibiotics at an early stage.

The doctor treating you often prescribes antibiotics for inhalation, because the active ingredients reach the target site (lungs) directly. Alternatively or additionally, taking antibiotics (e.g. in the form of tablets) can also be indicated.

For severe infections, antibiotics often need to be given by vein. This can be necessary, for example, in the case of chronic infections with Pseudomonas aeruginosa.

Fungus-related respiratory infections can be treated with antifungal agents. Virus-inhibiting drugs can often help with viral respiratory infections.

Anti-inflammatory drugs

In many patients, the airways are frequently or chronically inflamed. Then anti-inflammatory drugs are used, especially glucocorticoids (cortisone). They can be inhaled, taken by mouth, or given by vein.

CFTR modulators

So-called CFTR modulators have been available for the treatment of cystic fibrosis for several years. These long-term medications can improve the function of the ion channels that are defective due to the CFTR mutation.

This can improve patients’ lung function, increase their weight, reduce salt levels in their sweat and reduce the incidence of lung infections.

However, these are mutation-specific therapies, which means that CFTR modulators are only effective for certain mutations and therefore only for certain patients. Some examples:

Ivacaftor was the first CFTR modulator to be approved in 2012. It can be prescribed to babies as young as 12 months and weighing at least seven kilograms if they have at least one so-called gating mutation (such as G551D).

Cystic fibrosis patients aged 12 years and older, in whom the disease is caused by two copies of the F508del mutation, can be treated with a combination of the two CFTR modulators ivacaftor and lumacaftor.

Researchers are working intensively on other drugs that help against other mutations underlying cystic fibrosis.

Physical therapies

Various physical therapy techniques help to free the airways from viscous bronchial secretions. These include drainage positioning, vibration drainage, tapping massage and cough training.

Parents of young children with cystic fibrosis can learn these respiratory therapy techniques and use them daily at home. Older children and adults with cystic fibrosis can perform respiratory therapy independently (after instruction from a therapist).

Lung transplant – the last hope

In severe cases of cystic fibrosis, a lung transplant is an option. As drastic as this step may seem at first, many patients can then lead a significantly less symptomatic life.

Eating right for cystic fibrosis

Since digestion is disturbed in cystic fibrosis, patients must pay close attention to their diet. Meals should provide enough calories and protein to support normal growth. A normal to high fat intake is also recommended.

Patients are given digestive enzymes to support the digestion of food. There are also preparations with fat-soluble vitamins (A, D, E, K) and minerals. The latter replace the salts, which the patients sweat out in large quantities.

A certain amount of table salt should be ingested with food throughout the day. Correspondingly more is required at high temperature, fever, diarrhea vomiting. A possible iron deficiency should be tested once a year and substituted if there is a deficiency.

Infants with cystic fibrosis

Babies with cystic fibrosis should be fed exclusively breast milk for the first four months while they are thriving. There is even evidence that breastfeeding for more than six months is associated with less disease severity.

According to research, breastfed infants have better lung function and fewer infections within the first three years of life than infants with cystic fibrosis who receive formula.

If feeding with breast milk is not possible, infants should be given commercial infant formula if they are thriving.

When babies with cystic fibrosis do not thrive, high-calorie formula is recommended (in addition to breast milk for breastfed children).

As far as the introduction of complementary food is concerned, the same recommendations apply as for healthy children: Parents should start feeding at the earliest at the beginning of the 5th month and at the latest at the beginning of the 7th month.

The diet of children with cystic fibrosis should be tailored so that the little ones thrive according to their age. It is important to avoid being overweight or underweight. A good quality diet is also advisable. Attention should be paid to good dietary fats (with mono and polyunsaturated fatty acids, omega-3 fatty acids).

The lung function and the growth of the air sacs (alveoli) are influenced by physical development in the first years of life. Therefore, children with cystic fibrosis in this age group should be regularly examined for their nutritional status (using measurements of weight, body length and head circumference).

Receive vaccinations

Vaccinations are particularly important for patients with cystic fibrosis. Bacteria have an easier time with them and they often become more seriously ill than patients who are not previously infected.

In principle, children with cystic fibrosis should receive all vaccinations that the Standing Vaccination Commission (STIKO) recommends for healthy offspring.

In addition, a hepatitis A vaccination is recommended for children from the age of 12 months and an annual flu vaccination with the quadrivalent inactivated influenza vaccine for children from the age of six months.

For babies under six months, all household members and caregivers should be vaccinated against the flu to protect the child.

In addition, children with cystic fibrosis can be given a drug (palivizumab) to prevent the pathogen RSV (respiratory syncytial virus). These viruses, which are spread all over the world, can cause respiratory diseases, especially in babies and small children.

Cystic fibrosis: disease course and prognosis

Cystic fibrosis is caused by a change in the genetic makeup and is therefore not curable. In general, life expectancy and quality of life are usually significantly reduced in cystic fibrosis. Without therapy, the state of health deteriorates rapidly and those affected usually do not live long.

With timely and consistent therapy, however, the course of the disease can be slowed down considerably. Patients are now living much longer than they were a few years ago. The average life expectancy for cystic fibrosis is currently around 50 years. However, many patients are also getting older.

Complications and sequelae

Even with intensive therapy, complications can occur again and again in cystic fibrosis. The most common cause is acute shortness of breath due to poor ventilation of the lungs. Individual areas of the lungs can even collapse.

Chronic bronchitis or pneumonia often develops. Fungi can also affect the lungs.

In addition, shifts in fluid and electrolyte balance can trigger shock and circulatory failure.

Other possible complications and sequelae of cystic fibrosis are:

  • Chronic liver disease, especially cirrhosis
  • Gallbladder inflammation and gallstones
  • Chronic pancreatitis
  • Disturbed heart function
  • Acute intestinal obstruction
  • Bowel invagination
  • Malnutrition
  • Diabetes mellitus
  • Reduced fertility in women and infertility in men

Cystic Fibrosis: Prevention

Cystic fibrosis is a hereditary disease, so it cannot be prevented. People with a family history of increased risk should seek genetic counseling if they wish to have children.

A genetic test is carried out and it is examined whether the CFTR gene is altered. Depending on whether one or both partners carry the defective gene, the risk for the offspring can be calculated.

Preimplantation diagnosis (PGD) is now possible in most European countries for cystic fibrosis under the legal provisions of the respective country.

The egg cells are fertilized outside the womb and only embryos without the problematic cystic fibrosis genes are used. The prerequisite for this is always the approval of an ethics committee.

Dr. Ashwani Kumar is highly skilled and experienced in treating major and minor general medicine diseases.