What Is Cystic Fibrosis (CF)?

Medically reviewed by Jonathan B. Jassey, DO

Cystic fibrosis (CF) is a hereditary disease that affects the respiratory, digestive, and reproductive systems.

The genetic mutation that drives CF causes a protein to become faulty, leading to issues with the areas of the body that create mucus and sweat, including cells, tissues, and glands.

CF is most commonly found in children by the time they reach 2 years of age. However, it can also be diagnosed later in life and into adulthood.

This article discusses the causes, symptoms, and complications associated with CF.

How Is Cystic Fibrosis Inherited?

A child must be born to two parents with the same genetic defect to inherit CF, which is referred to as an autosomal recessive disorder.

The gene responsible for CF, called CFTR, plays a role in encoding cells known as epithelial ions. The body uses these cells to create adequate levels of mucus and to clear out excess mucus so it doesn’t build up.

People with CFTR gene mutations (changes) do not have signs of the disease but can pass it on to their unborn children. If a child receives only one copy of the gene, they will not develop CF but will become carriers.

If both parents have the same gene mutation, their child has a 25% chance of developing CF.

CF is a fatal disease, but many people with CF can receive treatment and maintain quality of life. The average life expectancy has increased over time due to medical advancements and is now at roughly 40 years old. That is the median, though; people can live well past 40 with CF depending on their disease progression and treatment plan.

Learn More:Cystic Fibrosis Facts and Statistics: What You Need to Know

What Causes Cystic Fibrosis?

The cause of CF is the inheritance of two faulty CFTR genes. The genes are considered faulty because they are not whole. Rather, part of the gene is missing, making the instructions the gene provides incomplete. These genes provide instructions to the CFTR protein.

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This specific protein plays a role in mucus and sweat production. The sweat of people with CF is much saltier than it should be, leading to excess salt loss from the body. Symptoms develop when the body lacks adequate salt stores.

When the protein's instructions are incomplete because of the mutation, the amount and consistency of the mucus change, leading to the symptoms of CF.

The single factor associated with developing CF is having two parents with the gene. White people are the most likely to develop CF.

Related:Cystic Fibrosis and the Term 65 Roses

Cystic Fibrosis Symptoms

CF is a progressive disease, meaning its symptoms worsen over time. CF affects different bodily systems, including the:

In Children

In infants and children, it can be difficult to determine all the signs since CF often develops early on in life, before a child can verbally express their symptoms. The first signs of neonatal CF include:

• Failure to thrive

• Chronic cough

• Bowel obstruction occurs during the infant's first bowel movement

• Inflammation of the nasal and sinus mucosa, the tissue that lines the sinus cavity

• Liver scarring caused by bile ducts becoming inflamed or swollen

• Blocked tubes in the reproductive tract

In infants, children, and young adolescents, the signs of CF may vary from person to person. However, there are some signs of disease that prompt investigation, including:

• Persistent diarrhea

• Bulky and foul-smelling stools

• Greasy stools

• Frequent wheezing

• Pneumonia infections

• Chronic cough with thick mucus

• Salty tasting skin

• Poor growth

Related:Progressive Disorders and Diseases

In Adults

Because the mucus becomes thicker and stickier as CF progresses, building up within the body, and because there is an increased loss of salt and water in the body, adults will experience more harmful health effects than children, including:

• Abnormal heart rhythms

• Malnutrition

• Recurring or frequent chest infections

• Difficulty breathing

• Wheezing

• Permanent lung damage

• Nasal polyps

• Rounding and enlargement of fingers or toes, known as clubbing

• Lung tissue ruptures leading to trapped air between the lungs and chest wall

• Coughing up blood

• Swelling or enlargement of the heart

• Abdominal pain or discomfort

• Gas buildup in the abdomen

These symptoms will vary from person to person, depending on how their bodies are affected by the disease.

Not everyone with CF will receive a diagnosis as a child. It’s entirely possible for the signs and symptoms to become more prominent as a person reaches adulthood. According to a case study published in 2020 in the journal Cureus, people can be diagnosed with CF well into their adult lives, with one female participant not getting diagnosed until age 57.

People diagnosed with CF later in life tend to have less severe cases.

Learn More:Symptoms of Cystic Fibrosis

How Is CF Diagnosed?

Newborns are screened for CF because of how important early diagnosis and treatment are. The diagnostic process for newborns includes a blood test. The blood sample is taken to a lab where a pathologist checks for elevated levels of a specific pancreatic chemical known as immunoreactive trypsinogen (IRT).

IRT is typically higher in people with CF, so this first diagnostic tool can identify CF early on and determine if more testing is needed. A downside of this test is that IRT can be high in other circumstances, as well, such as:

DNA testing may also be done to check for CF.

Another test used to diagnose CF is the sweat test, which looks for high levels of sodium chloride (salt) in the sweat, typical of someone with CF.

The sweat test is the most common type of testing for people of any age experiencing CF symptoms. To perform the sweat test, healthcare providers apply a chemical to the skin that induces sweat. Once enough sweat has been produced, the sample is collected and analyzed for excessive salt.

Other possible testing options used in the diagnosis of CF in people of all ages can include:

• Chest X-rays to examine the level of mucus buildup

• Sputum cultures to examine mucus

• Stool examinations to check for digestive markers of CF

• Lung function tests

• Lung cultures, such as bronchoscopy or throat swab

• Pancreatic function tests (stool pancreatic elastase)

• Secretin stimulation test

The types of tests used will vary depending on the individual and include the symptoms they are experiencing and the results gleaned from the preliminary screenings.

CF genetic testing can be performed on adults during family planning to determine if future children are at risk of having CF. It will depend on whether each partner has the CFTR gene.

Learn More:Cystic Fibrosis Carrier Testing

Cystic Fibrosis Complications

The most common complication found in CF is recurrent and chronic respiratory infections because of how the disease affects the lungs. Other body parts and systems are affected by CF and can cause the following:

• Gallstones

• Intestinal blockages

• Rectal prolapse (the lowest part of the large intestine slips outside the anus)

• Coughing up blood

• Respiratory failure

• Diabetes

• Infertility

• Liver disease

• Liver failure

• Pancreatitis

• Biliary cirrhosis (bile ducts become swollen, blocking the flow of bile and scarring the liver)

• Malnutrition

• Nasal polyps

• Sinusitis

• Osteoporosis (thinning and weakening of bones) and arthritis

• Recurrent pneumonia

• Pneumothorax (air is outside the lung but within the pleural cavity inside the chest)

• Cor pulmonale (right-sided heart failure)

• Colorectal cancer (cancer of the colon and/or rectum)

If you or your child has CF, exhibiting symptoms requires medical attention. Symptoms to watch out for include:

• Fever

• An increase in coughing or coughing up blood

• Changes in sputum, blood in sputum

• Loss of appetite

• Increased weight loss

• Frequent bowel movements that contain more mucus than usual

• An increase in bloating or a swollen stomach

• Severe difficulty breathing

Cystic Fibrosis Treatment

Treating CF can be complicated because of how many areas of the body the disease affects. However, various treatments are available to help manage symptoms and improve quality of life in those with CF. They include airway clearance, medication, complementary and alternative medicine (CAM) therapies, supportive therapies, and surgery.

Airway Clearance

Ensuring the airways are clear is crucial for people with CF. Some possible techniques to do so include using:

• Special breathing or coughing techniques

• Devices placed in the mouth or therapy vests to loosen mucus through vibrations

• Chest physical therapy

Medication

Medications for CF provide relief for several symptoms associated with the disease. They are meant to keep the lungs clear of infection, improve the function of the lungs, and help with breathing. Some medications used to treat CF are:

• Antibiotics to prevent lung infections

• Anti-inflammatory medications, such as nonsteroidal anti-inflammatories (NSAIDs) and corticosteroids, to reduce inflammation

• Bronchodilators, which are inhaled and work by opening the airways

• CFTR modulators, which are medications to help the faulty protein that lends a hand to CF development function better

• Mucus thinners, which are inhaled medications that make it easier for someone with CF to clear excess mucus from their airways

CAM Therapies

Holistic or complementary and alternative medicine therapies can be used alongside medical treatments to help improve the quality of life in people with CF. Some possible therapies used for both adults and children include:

Supportive Therapies

When CF symptoms become more severe, people may want to opt for more supportive therapies on top of their current treatment plan. Some possible supportive therapies include:

Surgery

Surgery is often reserved for people with severe cases of CF. People with severe lung involvement may get a lung transplant, while those with advanced liver disease can receive a liver transplant.

CF affects people differently, and there is no one-size-fits-all treatment. Because there are so many options geared toward reducing symptoms, a multipronged approach is needed when treating CF symptoms and improving quality of life.

Related:What to Know About Telehealth for Cystic Fibrosis

Living a Healthy Life With Cystic Fibrosis

Living with CF is challenging, but a person’s quality of life can be improved by engaging in healthy lifestyle practices. Monitoring your condition is crucial to coping well with the disease because it can help you keep track of how the disease is affecting you. That way, if anything changes or symptoms worsen, you can pivot your treatment plan quickly.

You can do this through regular checkups with a healthcare provider that include:

• Education about nutrition goals, airway clearance, and infection control

• Weighing yourself and checking your body mass index (BMI) to maintain a healthy weight.

• Participating in physical therapy

• Seeking out psychological support for any feelings of depression or anxiety that may go along with CF

• Asking a healthcare provider for further testing on an ongoing basis to watch for changes

Your lifestyle also matters when you have CF. There are a few changes you can make to help better reduce symptoms, such as:

• Not smoking and avoiding secondhand smoke

• Improving lung function through physical exercise

• Eating whole foods that are rich in nutrients to prevent malnutrition

While it may seem daunting to stay on top of your condition in so many different ways, it’s essential to keep up with your treatment plan.

Learn More:What to Eat When You Have Cystic Fibrosis

CF Support and Resources

For further support, people with CF can access many resources. Resources can help with education, community, and psychological distress caused by CF. Some good places to turn to for extra support while you cope and treat your disease include:

Finding the right support can make all the difference in coping and living well with CF.

Read Next:Living With Cystic Fibrosis