Cystic Fibrosis

Medically Reviewed By William C. Lloyd III, MD, FACS

What is cystic fibrosis?

Cystic fibrosis (CF) is an inherited disease that affects the lungs, intestines, liver and pancreas. In cystic fibrosis, mucus-producing glands make excessive amounts of abnormally thick and sticky mucus. This thick mucus clogs and obstructs the body’s digestive tract and air passages. The excessive mucus leads to serious problems with digestion and breathing, which often results in an early death. Cystic fibrosis is one of the most common chronic lung diseases in children and young adults.

Cystic fibrosis most often affects the lungs and pancreas. In healthy lungs, air and oxygen pass through the upper respiratory tract, down into the bronchioles and alveoli. Alveoli are tiny sac-like structures. They transfer oxygen from the lungs into the bloodstream. In cystic fibrosis, a buildup of thick, sticky mucus in these airways makes breathing and oxygen transfer less effective. Extra mucus also encourages the growth of bacteria and viruses, causing chronic lung infections.

Cystic fibrosis can also cause serious problems with the pancreas. This organ produces enzymes that are important for food digestion. Cystic fibrosis can cause mucus to block the ducts that carry enzymes from the pancreas to the digestive tract. This leads to abnormal digestion, malnutrition, and vitamin and mineral deficiencies.

Cystic fibrosis is usually diagnosed in infancy and early childhood. The disease is progressive and can eventually be fatal. However, an early cystic fibrosis diagnosis and regular medical care can greatly extend life expectancy. Cystic fibrosis life expectancy has increased dramatically in recent decades thanks to new and improved treatments. In the 1950s, children usually died as infants or toddlers. Today, the average life span is about 35 years. However, some people with cystic fibrosis are living into their 40s, 50s and older.

Cystic fibrosis can lead to serious and life-threatening complications. This includes nutritional deficiencies, diabetes, chronic lung infections, and respiratory failure. Seek prompt medical care for cystic fibrosis symptoms, such as growth delays, weight loss, a cough that does not go away, excessively salty sweat or skin, and constipation or greasy, foul-smelling stools.

Seek immediate medical care (call 911) for potentially serious symptoms, such as severe shortness of breath, severe difficulty breathing, chest pain, or an unexplained decrease in alertness or consciousness.

What are the symptoms of cystic fibrosis?

Typically, symptoms of cystic fibrosis and its complications affect the lungs and the digestive system. However, the symptoms and their severity vary from person to person. Not all people will have symptoms in both body systems.

Cystic fibrosis symptoms that affect the respiratory system

Cystic fibrosis symptoms usually affect the lungs. Thick, sticky mucus builds up in the airways, making it hard to breathe. This causes shortness of breath and a chronic cough. Mucus buildup also encourages the growth of bacteria and viruses, leading to chronic lung infections.

Common respiratory symptoms include:

  • Chronic cough

  • Coughing up thick sputum that may contain blood

  • Fatigue with or without exertion

  • Frequent or chronic lung infections such as pneumonia

  • Nasal congestion

  • Shortness of breath

  • Sinus pain or pressure

  • Symptoms of respiratory infections, such as fever and malaise

Cystic fibrosis symptoms that affect the digestive system

Cystic fibrosis can cause serious problems with digestion and absorption of nutrients. In particular, it causes thick mucus to block the ducts that carry enzymes from the pancreas to the digestive tract.

Common digestive symptoms include:

  • Abdominal pain

  • Constipation

  • Feces that are fatty, greasy, unusually foul smelling, or unusually pale

  • Gas (flatulence), bloating, and abdominal swelling

  • Growth delays and failure to gain weight in infants and children

  • Lack of a bowel movement in first day or two of life in a newborn

  • Nausea

  • Nutritional deficiencies and malnutrition

  • Poor appetite

  • Weight loss

  • Yellowing of the skin and whites of the eyes (jaundice) due to liver dysfunction

Other symptoms of cystic fibrosis

Symptoms of cystic fibrosis and its complications outside the digestive and respiratory systems include:

Symptoms that might indicate a serious or life-threatening condition

Cystic fibrosis can lead to serious complications. This includes diabetes, respiratory failure, liver failure, and heart failure. Seek immediate medical care (call 911) for any of the following symptoms:

  • Change in consciousness or alertness including lethargy, unresponsiveness, passing out, confusion, or disorientation

  • Severe abdominal pain

  • Severe difficulty breathing including shortness of breath or wheezing (high-pitched whistling sound made with breathing)

What causes cystic fibrosis?

Cystic fibrosis is an inherited disease. It is caused by a mutation in the CFTR gene. This change triggers the mucus-producing glands of the body to make excessive amounts of abnormally thick and sticky mucus. A person must inherit two copies of the defective gene, one from each parent, to develop cystic fibrosis. Each parent of an affected person carries one copy of the defective gene, but they do not usually show symptoms of the disease.

Cystic fibrosis is traditionally diagnosed in children. However, an increasing number of adults who have had recurring bouts of pneumonia are being diagnosed with the disease as well.

What are the risk factors for cystic fibrosis?

The major risk factor for cystic fibrosis is a family history of the disease. The defective gene is passed down through families. You must inherit two copies of the defective cystic fibrosis gene, one from each of your parents, to develop the disease. The defective gene is more common in people of Northern and Central European ancestry.

Reducing your risk of cystic fibrosis

It is not possible to prevent cystic fibrosis. However, couples with a family history of the disease who are planning to start a family can seek genetic counseling. This service can determine if either or both prospective parents carry the defective cystic fibrosis gene (CFTR).

What are the diet and nutrition tips for cystic fibrosis?

Several aspects of cystic fibrosis may require you to adjust your diet. Overall, a healthy balanced diet is more important than ever. This is especially true for children to encourage growth and development. Your doctor may also recommend the following dietary measures:

  • Adding extra salt to your diet during certain times, such as when exercising or in hot weather

  • Drinking extra fluids to help thin mucus

  • Eating extra fiber to aid in digestion and prevent constipation and blockages

  • Increasing caloric intake by eating high-calorie foods or more food each day 

  • Taking fat-soluble vitamin supplements

  • Using supplemental nutrition drinks or bars

Ask your healthcare provider for guidance before making significant changes to your diet.

How do doctors diagnose cystic fibrosis?

In the United States, hospitals routinely screen newborns for cystic fibrosis. They use an IRT (immunoreactive trypsinogen) blood test by taking a heel prick. IRT is a chemical that comes from the pancreas. IRT is higher in babies with cystic fibrosis. However, it can also be high in babies who are premature or who had a stressful delivery. So, follow-up testing is necessary to confirm a diagnosis.

At two weeks of age, doctors can test babies with a sweat test. They apply a sweat-producing chemical to the skin and collect the sweat. Then, they test it for salt content to see if it is higher than normal. Doctors may also order genetic testing to check for the gene mutations responsible for cystic fibrosis. These two tests can also diagnose the disease when older infants, children or adults develop symptoms.

How is cystic fibrosis treated?

There is no cure for cystic fibrosis. Early diagnosis and commitment to your treatment program can help reduce symptoms and complications, and extend life. Cystic fibrosis treatment is multifaceted. Doctors tailor treatment to your specific symptoms, the presence of other diseases, your age and medical history, and other factors.

The goals of treatment are to keep the airways in the lungs open, minimize symptoms, and prevent complications.

Drug treatment of cystic fibrosis

Doctors treat cystic fibrosis with a variety of medications. The ones you need will vary depending on the specific symptoms and affected body systems. Medications can include:

  • Antibiotics to treat bacterial pneumonia and other bacterial lung infections

  • Bronchodilators to help relax and open up the lower airways in the lungs

  • Digestive enzymes to help with digestion

  • DNase enzyme treatment to thin mucus and make it easier to cough up and keep the airways clear

  • Oxygen therapy to treat moderate to severe cystic fibrosis, which results in low levels of oxygen in your blood

  • Steroid inhalers to reduce airway inflammation

  • CFTR modulators (Ivacaftor, Lumacaftor) that counteract a defective protein in select cystic fibrosis patients

  • Vitamins and other nutritional supplements to minimize vitamin deficiencies and malnutrition

Other treatments of cystic fibrosis

Doctors may also recommend a variety of therapies, lifestyle and dietary interventions, and possibly surgery. Other treatments of cystic fibrosis include:

  • Chest physical therapy, such as chest percussion and postural drainage, which are techniques performed daily to several times a day to physically loosen and remove mucus in the lungs

  • High-protein, high-calorie diet

  • Lung transplant

  • Participation in a clinical trial that is testing promising new treatments

  • Pulmonary rehabilitation, which is a medically supervised exercise program

  • Regular but moderate exercise program

  • Staying hydrated by drinking lots of fluids to keep mucus as loose as possible

  • Vaccination and other prevention measures to avoid diseases that can seriously complicate cystic fibrosis and become life-threatening, such as pneumonia, COVID-19 and flu

Because cystic fibrosis is caused by defects in a specific gene, scientists have been studying gene therapy for cystic fibrosis for many years. There are significant hurdles to selectively deliver gene therapy to lung cells, and it will likely be years until large scale clinical trials can be conducted in people with cystic fibrosis.

How does cystic fibrosis affect quality of life?

Quality of life and emotional wellness can be challenging for people with a chronic disease like cystic fibrosis. Research suggests people with mild cystic fibrosis have similar psychological and psychosocial functioning to well people. When the disease is severe, quality of life and emotional wellness can suffer. When symptoms interfere with life, people with cystic fibrosis have a higher risk of anxiety and depression. Fear and anger are other common emotions. These feelings and emotions are possible at all stages of life. However, the specific challenges may change by age.

School-aged children with cystic fibrosis tend to be smaller and thinner than their peers. This can lead to body-image problems and stress. Treatments, feeding, and absences due to illness can make these kids feel drastically different from their peers. This can lead some children to neglect vital aspects of their care in an attempt to reduce the differences.

In teens, puberty, growth spurts, and menstruation can be delayed. This can further contribute to feeling different. Teens are also taking on many of the responsibilities for their own care. The extra pressure on top of normal adolescent stresses can be a lot to handle.

Adults with cystic fibrosis also have their own challenges. The disease tends to progress with time, so symptoms and complications may worsen in adulthood. There is also the issue of starting a family. Most men are infertile and most women usually have problems conceiving.

At every stage of life, support and coping are invaluable tools for living with cystic fibrosis. Support groups are a popular choice for people living with the disease. They provide a place to share experiences and be with others who share the journey.

What are the potential complications of cystic fibrosis?

Complications of cystic fibrosis are serious, progressive, and eventually become life-threatening and fatal. Respiratory failure is the most common cause of death in people with cystic fibrosis. You can reduce the risk of serious complications or delay their development by following the treatment plan you and your healthcare provider design specifically for you. Complications of cystic fibrosis can include:

  • Diabetes

  • Disability

  • Gastrointestinal conditions, such as pancreatitis, gallstones, and intestinal obstruction

  • Growth deficiencies in children and infants

  • Heart failure

  • Infertility

  • Lung disease, such as asthma, permanent lung damage, and respiratory failure

  • Recurrent and chronic sinus infections and lung infections, such as bronchitis and pneumonia

  • Serious liver problems, such as cirrhosis, portal hypertension, and liver failure

  • Sinus infections

  • Skeletal diseases, such as arthritis and osteoporosis

  • Vitamin and mineral deficiencies and malnutrition

Does cystic fibrosis shorten life expectancy?

In 1966, the Cystic Fibrosis Foundation (CFF) created a Patient Registry. The registry tracks the health and statistics of people who receive care at a CFF-accredited center. It is a useful tool for following general trends in the population of cystic fibrosis patients.

The registry shows that people with cystic fibrosis are living longer and healthier lives. The latest data predict that people born with cystic fibrosis between 2015 and 2019 have a median life expectancy of 46 years. A median is a halfway point in a data set. So, half the people in this group will live past 46 years. Compared to the period of 1995 to 1999, this number has increased from a median 32 years.

The registry also reports the median age of death. In 2019, it was 32 years. Half the deaths occurred before this age and half occurred after it.

Keep in mind, statistics alone cannot tell you how long any one person with the disease will live. Many factors determine a person’s outlook. This includes disease severity and how the disease responds to treatment. It also takes time for statistics to catch up to treatment advances, such as CFTR modulators. Your doctor is always the best source of information about your individual prognosis.

Was this helpful?
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  2. Cystic Fibrosis. Mayo Foundation for Medical Education and Research. 
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  4. Cystic Fibrosis (CF). American Lung Association. 
  5. Cystic Fibrosis Transmembrane Conductance Regulator; CFTR. Online Mendelian Inheritance in Man. 
  6. Davis PB. Another beginning for cystic fibrosis Therapy. N Engl J Med 2015;373:274.
  7. Living With Cystic Fibrosis. Cystic Fibrosis News Today. 
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  9. Understanding Changes in Life Expectancy. Cystic Fibrosis Foundation. 
  10. What Is Cystic Fibrosis? National Heart Lung and Blood Institute, National Institutes of Health 

Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Oct 6
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