Cystic fibrosis mucus can cause blockages and increased risk of infections. Cystic fibrosis treatments focus on reducing and clearing the mucus.

Cystic fibrosis is a genetic condition that causes mucus in the body to be thicker and stickier than normal.

This can cause problems throughout the body, including breathing difficulties, recurrent infections, and digestive issues.

This article looks at the causes, symptoms, and treatment of cystic fibrosis mucus.

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Mucus is a clear, slippery substance that comes from membranes lining organs in the body. It helps to protect tissues and organs in the body, including the digestive tract and airways.

Cystic fibrosis causes this mucus to be thicker and stickier than usual, which can result in blockages, trap germs — which can lead to infections — and prevent certain processes in the body from working as normal.

People with cystic fibrosis have a genetic mutation that causes a fault with the cystic fibrosis transmembrane conductance regulator (CFTR) protein.

If the CFTR protein is not working properly, it cannot move chloride around as usual.

Chloride forms part of salt, and it draws water to the cells’ surfaces, which makes normal mucus slippery and able to carry out its role of protecting organs and tissues.

Faults in this process mean the mucus becomes dehydrated due to the lack of water. It becomes thick and sticky instead, which causes problems throughout the body. The abnormal mucus can build up and cause damage to organs, blockages, and infections.

Cystic fibrosis mucus can affect multiple organs, tissues, and systems throughout the body.

The two main areas that cystic fibrosis mucus affects are the respiratory and digestive systems.

Mucus can build up in the airways and trap bacteria or other germs. Respiratory symptoms of cystic fibrosis mucus can include:

Mucus buildup in the pancreas can prevent the release of digestive enzymes. Without these digestive enzymes, the body is unable to properly absorb food and get the nutrients it needs, leading to stunted growth and malnutrition.

Digestive symptoms of cystic fibrosis mucus can include:

  • severe constipation
  • foul-smelling, greasy stools
  • feeling constant hunger
  • inability to gain weight
  • intestinal blockage

Currently, there is no cure for cystic fibrosis, but there are ways to manage cystic fibrosis mucus and prevent complications.

Clearing the airways

Various techniques can help to loosen and clear out mucus from the lungs. This helps to ease breathing difficulties and reduce the risk of infections.

Airway clearance techniques include:

  • special techniques for coughing and breathing
  • mouthpieces or oral devices that make people breathe out with increased pressure, which loosens trapped mucus from the airways
  • chest physical therapy, or postural drainage, which is a manual therapy to loosen mucus and may include clapping on the chest wall
  • special vests that apply a vibration to the chest, which loosens mucus for people to cough up
  • bronchodilators, which are medications to relax and widen the airways and ease breathing difficulties
  • medications that thin out mucus


Medications for cystic fibrosis can help the dysfunctional CFTR protein, which causes cystic fibrosis mucus, to work better. Medications may also help to clear mucus, improve breathing and lung function, and treat or prevent infections. They include:

  • antibiotics to fight or prevent infections in the lungs
  • anti-inflammatory drugs to reduce the inflammation that occurs with cystic fibrosis
  • CFTR modulators to help improve the function of the CFTR protein, which may help to reduce lung symptoms

CFTR modulators may not be suitable for everyone with cystic fibrosis, as it depends on the specific genetic mutation each person has. People will have genetic testing to find out if this type of medication is an option.

A pancreatic enzyme supplement can also help increase the absorption of nutrients. Multivitamins also help make sure people with cystic fibrosis get the nutrients they require.

It is not possible to prevent cystic fibrosis or cystic fibrosis mucus, as the condition is genetic.

People who are pregnant, or planning to become pregnant, can undergo screening to check if a child may be born with cystic fibrosis, although this does not cover all the genetic mutations that can cause cystic fibrosis.

If a person has a family history of cystic fibrosis, they can talk with a doctor about genetic counseling and testing.

Research is currently looking into new treatments for managing cystic fibrosis mucus. This includes a further CFTR modulator drug and a drug that works to regulate levels of fluids and salt on cell surfaces in the airways, which may help reduce mucus in the airways.

This section answers some frequently asked questions about cystic fibrosis mucus.

What is the average lifespan of a person with cystic fibrosis?

According to a 2022 article, the predicted average lifespan of a person born in 2019 in the United States with cystic fibrosis is 48.4 years. The basis for this is data from a Cystic Fibrosis Foundation Registry Report.

Other data from around the world suggest an average lifespan ranging from 44 to 53 years.

What are three major symptoms of cystic fibrosis?

Three of the main symptoms of cystic fibrosis are:

  • very salty-tasting skin
  • respiratory problems, such as chronic cough, breathing difficulties, and recurrent chest infections
  • poor growth and malnutrition

Cystic fibrosis causes a fault in the CFTR protein, which leads to mucus within the body to be thick and sticky.

This affects multiple organs and tissues throughout the body and can cause issues such as respiratory and digestive problems.

Although there is no cure or prevention for cystic fibrosis mucus, treatments can help to manage it and reduce complications. Treatment may include airway clearance techniques and medications to reduce and clear mucus.