About Cystic Fibrosis

Learn about cystic fibrosis, a genetic disorder that affects the lungs, pancreas, and other organs, and how to treat and live with this chronic disease.

What Is Cystic Fibrosis?

Cystic fibrosis is a progressive, genetic disease that causes persistent lung infections and limits the ability to breathe over time.

In people with CF, mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause the CFTR protein to become dysfunctional. When the protein is not working correctly, it’s unable to help move chloride -- a component of salt -- to the cell surface. Without the chloride to attract water to the cell surface, the mucus in various organs becomes thick and sticky.

In the lungs, the mucus clogs the airways and traps germs, like bacteria, leading to infections, inflammation, respiratory failure, and other complications. For this reason, minimizing contact with germs is a top concern for people with CF.

In the pancreas, the buildup of mucus prevents the release of digestive enzymes that help the body absorb food and key nutrients, resulting in malnutrition and poor growth. In the liver, the thick mucus can block the bile duct, causing liver disease. In men, CF can affect their ability to have children.

Symptoms of CF

People with CF can have a variety of symptoms, including:

  • Very salty-tasting skin
  • Persistent coughing, at times with phlegm
  • Frequent lung infections including pneumonia or bronchitis
  • Wheezing or shortness of breath
  • Poor growth or weight gain in spite of a good appetite
  • Frequent greasy, bulky stools or difficulty with bowel movements
  • Male infertility
Jay, a 6-year-old with CF

Listen to CF clinicians explain:

  • Which body parts are affected by CF
  • Common CF symptoms
  • How CF is treated

Diagnosis and Genetics

Cystic fibrosis is a genetic disease. People with CF have inherited two copies of the defective CF gene -- one copy from each parent. Both parents must have at least one copy of the defective gene.

People with only one copy of the defective CF gene are called carriers, but they do not have the disease. Each time two CF carriers have a child, the chances are:

  • 25 percent (1 in 4) the child will have CF
  • 50 percent (1 in 2) the child will be a carrier but will not have CF
  • 25 percent (1 in 4) the child will not be a carrier and will not have CF

The defective CF gene contains a slight abnormality called a mutation. There are more than 1,700 known mutations of the disease. Most genetic tests only screen for the most common CF mutations. Therefore, the test results may indicate a person who is a carrier of the CF gene is not a carrier.

Diagnosing cystic fibrosis is a multistep process, and should include a newborn screening, a sweat test, a genetic or carrier test, and a clinical evaluation at a CF Foundation-accredited care center. Although most people are diagnosed with CF by the age of 2, some are diagnosed as adults. A CF specialist can order a sweat test and recommend additional testing to confirm a CF diagnosis.

Read the CF Foundation’s clinical care guidelines for diagnosing CF.

According to the Cystic Fibrosis Foundation Patient Registry, in the United States:

  • More than 30,000 people are living with cystic fibrosis (more than 70,000 worldwide).
  • Approximately 1,000 new cases of CF are diagnosed each year.
  • More than 75 percent of people with CF are diagnosed by age 2.
  • More than half of the CF population is age 18 or older. 

Did You Know?

More than half of the cystic fibrosis population is over 18.

What to Expect

Cystic fibrosis is a complex disease and the types and severity of symptoms can differ widely from person to person. Many different factors, such as age of diagnosis, can affect an individual's health and the course of the disease.

Watch a video that provides a glimpse into the everyday life of Kaitlyn Broadhurst, a 25-year-old living with cystic fibrosis.

Tremendous advancements in specialized CF care have added years and quality of life to the lives of people with cystic fibrosis. There have been dramatic improvements from the 1950s, when a child with CF rarely lived long enough to attend elementary school to today, with many living long enough to realize their dreams of attending college, pursuing careers, getting married, and having kids.

Although there has been significant progress in treating this disease, there is still no cure and too many lives are cut far too short.


The type and severity of CF symptoms can differ widely from person to person. Therefore, although treatment plans can contain many of the same elements, they are tailored to each individual's unique circumstances.

Tré, a 24-year-old with CF, wearing his vest.

People with CF and their families have expertise in how the disease affects them and how the context of their daily lives affect the way they approach their care. By acknowledging the respective roles, people with CF, their families, and clinical care teams can work together to develop treatment plans that align personal life goals with health goals.

“My doctor and I decided to come up with a plan that would work for me. We were able to negotiate a deal so that I was doing more treatments than I had been, but I wasn’t just sitting at home hooked up to machines.” –-- Betsy Sullivan, a teenager with CF, from the CF Community Blog

The CF Foundation accredits more than 130 care centers that are staffed by dedicated healthcare professionals who provide expert CF care and specialized disease management.

Each day, people with CF complete a combination of the following therapies:

  • Airway clearance to help loosen and get rid of the thick mucus that can build up in the lungs. 
  • Inhaled medicines to open the airways or thin the mucus. These are liquid medicines that are made into a mist or aerosol and then inhaled through a nebulizer and include antibiotics to fight lung infections and therapies to help keep the airways clear.
  • Pancreatic enzyme supplement capsules to improve the absorption of vital nutrients. These supplements are taken with every meal and most snacks. People with CF also usually take multivitamins. 
  • An individualized fitness plan to help improve energy, lung function, and overall health
  • CFTR modulators to target the underlying defect in the CFTR protein. Because different mutations cause different defects in the protein, the medications that have been developed so far are effective only in people with specific mutations.

The CF Foundation supports research to discover and develop new CF treatments and maintains a pipeline of potential therapies that target the disease from every angle. 

Today, the Foundation is focused on developing lifesaving new therapies for larger numbers of people with CF -- including those with rare and nonsense mutations -- and pursuing daring, new opportunities to one day develop a lifelong cure. 


When a group of parents started the Cystic Fibrosis Foundation in 1955, there were no treatments for cystic fibrosis. These parents set their sights high -- to advance understanding of this little-known disease, to create new treatments and specialized care for their children, and to find a cure.

In the ensuing years, the fundraising and commitment of the CF community has enabled the Foundation to support fundamental research in the laboratory that has led to groundbreaking discoveries, including the identification of the gene and protein responsible for cystic fibrosis. By expanding our knowledge of the underlying biology of the disease and its effect on the body, researchers have paved the way for creating new treatments.

The Foundation's steadfast commitment to advancing CF research has helped enable more than a dozen new treatments for the disease. We have made incredible progress, including the approvals by the U.S. Food and Drug Administration (FDA) of ivacaftor (Kalydeco®), lumacaftor/ivacaftor (Orkambi®), tezacaftor/ivacaftor (Symdeko®), elexacaftor/tezacaftor/ivacaftor (Trikafta™), Cayston®, and tobramycin (TOBI®).

Watch this video to see how clinical research has made a difference in the lives of people with CF.

Research by dedicated scientists and clinicians from a wide range of disciplines advances our understanding of cystic fibrosis every day, helping to shape clinical care practices for people living with the disease for years to come. These include studies conducted using patient data in the CF Foundation's Patient Registry, which are helping us identify trends and track the effectiveness of treatments.

From bench to bedside, the Foundation is supporting the best research here and abroad to improve the quality of life of people with CF today and accelerate innovative research and drug development to add tomorrows. Two major initiatives have launched recently that will help us in this mission.

In 2018, the Foundation announced that it was committing $100 million to the Infection Research Initiative, a comprehensive approach to improve outcomes associated with infections through enhanced detection, diagnosis, prevention, and treatment. The Foundation also is actively pursuing and funding a broad portfolio of new treatments for other complications of the disease, such as inflammation, excessive mucus, gastrointestinal problems, and cystic fibrosis-related diabetes.

The second major initiative concentrates on people with nonsense and rare mutations who will not benefit solely from CFTR modulators and need an effective treatment for the underlying cause of their disease. The Foundation has thus far committed over $72 million to the Nonsense and Rare Mutations Research and Therapeutics Initiative, a multifaceted effort that already has funded more than 60 projects over the past several years at both academic institutions and pharmaceutical companies.

By pursuing these bold strategies and others, the CF Foundation continues to build a robust pipeline of potential new therapies that fight the disease from every angle. Learn more about the CF Foundation's key research programs:

  • Research Overview: A broad look at how the Foundation supports basic science, clinical research, and real-world research to expand our knowledge of cystic fibrosis and translate discoveries and insights into vital new treatments and clinical care practices for people living with CF.
  • Research We Fund: See a snapshot of how the CF Foundation is funding cystic fibrosis research.
  • CF Foundation Therapeutics Laboratory: Based in Lexington, Mass., the CF Foundation Therapeutics Laboratory identifies and tests potential groundbreaking therapies for CF, readying them for further development.
  • Therapeutics Development Network: The Therapeutics Development Network is the largest CF clinical trials network in the world. It provides the resources and support for studies that are leading to important new therapies and better treatments.
  • New Developments in Clinical Research: Watch interviews with leading CF researchers to learn about the latest cutting-edge studies into issues such as infections, nontuberculous mycobacteria (NTM), and nutrition and gastrointestinal health.
  • Drug Development Pipeline: Discoveries from the laboratory are being turned into potential drugs that attack both the symptoms of CF and the cause -- a faulty gene that makes a defective protein.
  • Research Centers: These CF "think tanks" are located at top universities and medical schools across North America, where scientists from many disciplines are brought together to combine their expertise to find a cure for CF.

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