Cystic Fibrosis: Causes, Diagnosis, and Treatment

Key takeaways

• Cystic fibrosis (CF) is a genetic condition caused by mutations in the CFTR gene, which makes mucus abnormally thick and sticky. This buildup damages the lungs, pancreas, liver, and intestines over time.
• Common symptoms include persistent cough with thick mucus, wheezing, shortness of breath, recurrent lung infections, greasy stools, constipation, and inadequate weight gain in children.
• While there’s no cure, treatment may include antibiotics, mucus-thinning medications, CFTR modulators, chest physical therapy, and nutritional support. Many people with CF now live into their 40s and 50s with proper management.

Cystic fibrosis (CF) is a serious genetic condition that causes severe damage to the respiratory and digestive systems. This damage often results from a buildup of thick, sticky mucus in the organs.

Regular, daily care can help manage CF, but there’s no one treatment plan that will work for everyone. With a treatment plan specific to your needs, you can still live a full life, attend school, and have a career.

In this article, we take a look at the symptoms, causes, diagnosis, and treatment of cystic fibrosis.

Cystic fibrosis affects the cells that produce sweat, mucus, and digestive enzymes. Normally, these fluids are thin and smooth like olive oil. They lubricate your organs and tissues, keeping them from getting too dry.

According to the Cystic Fibrosis Foundation, more than 30,000 people in the United States have cystic fibrosis, and another 1,000 people are diagnosed with it every year. CF is a progressive condition, so it gets worse over time.

If you have CF, a genetic mutation increases the thickness of mucus and other body fluids. When this happens, the thicker fluids can interrupt the function of organs — like the movement of air through your lungs. This can trap bacteria and lead to infections.

In more advanced cases, people with CF may have complications like respiratory failure and malnutrition.

It’s critical to get treatment for CF right away. Early diagnosis and treatment can improve quality of life and lengthen one’s life span.

Screening tests and treatment methods have improved in recent years, so many people with CF can now live into their 40s and 50s.

The symptoms of cystic fibrosis can vary depending on the person and the severity of their condition. The age at which symptoms develop can also differ.

Symptoms may appear in infancy, but for other children, symptoms may not begin until after puberty or even later in life. As time passes, the symptoms associated with the disease may get better or worse.

One of the first signs of CF is a strong, salty taste to the skin. Parents of children with CF have mentioned noticing this saltiness when kissing their children.

Other symptoms of CF result from complications that affect the:

• lungs
• pancreas
• liver
• other glandular organs

Respiratory problems

The thick, sticky mucus associated with CF often blocks the passageways that carry air into and out of the lungs. This can cause the following symptoms:

• wheezing
• persistent cough that produces thick mucus or phlegm
• shortness of breath, especially when exercising
• recurrent lung infections
• stuffy nose
• stuffy sinuses

Digestive problems

The abnormal mucus can also plug the channels that carry the enzymes produced by the pancreas to the small intestine. Without these digestive enzymes, the intestine can’t absorb the necessary nutrients from food. This can result in:

• greasy, foul-smelling stools
• constipation
• nausea
• abdominal swelling
• loss of appetite
• insufficient weight gain in children
• delayed growth in children

CF occurs as a result of a defect in what’s called the “cystic fibrosis transmembrane conductance regulator” gene, or CFTR gene. This gene controls the movement of water and salt in and out of your body’s cells.

A sudden mutation, or change, in the CFTR gene causes your mucus to become thicker and stickier than it’s supposed to be.

This abnormal mucus increases the amount of salt in your sweat and builds up in various organs throughout the body, including the:

• intestines
• pancreas
• liver
• lungs

Different defects can affect the CFTR gene. The type of defect is associated with the severity of CF. The damaged gene is passed on to the child from their parents.

In order to have CF, a child must inherit one copy of the gene from each biological parent. If they only inherit a copy of the gene from one parent, they won’t develop the disease. However, they’ll be a carrier of the defective gene, which means they may pass the gene on to their own biological children.

How likely you are to inherit CF depends on several factors.

Anyone can inherit CF if their parents carry the gene. However, carriers usually have just one copy of a defective gene and may never experience symptoms or even know they carry the gene.

According to the Cystic Fibrosis Foundation, about 10 million people in the United States are carriers of the gene for CF, yet only about 30,000 have active disease.

Although carriers won’t have active disease, the children of two carriers have a much higher risk. To be exact, if both your parents carry the cystic fibrosis gene, there is a:

In terms of ancestry or ethnic backgrounds, a

People who have a family history of CF are also at an increased risk because it’s an inherited disorder.

The diagnosis of CF requires clinical symptoms consistent with CF in at least one organ system and evidence of CFTR dysfunction. This evidence is usually based on abnormal results from a sweat chloride test or the presence of mutations in the CFTR gene.

Clinical symptoms are not required for infants identified through newborn screening. Other diagnostic tests that may be performed include:

• Immunoreactive trypsinogen (IRT) test: The IRT test is a standard newborn screening test that checks the blood for abnormal levels of the protein called IRT. A high level of IRT may be a sign of CF. However, further testing is required to confirm the diagnosis.
• Sweat chloride test: The sweat chloride test is the most commonly used test for diagnosing CF. It checks for increased levels of salt in the sweat. The test is performed by using a chemical that makes the skin sweat when triggered by a weak electric current. Sweat is collected on a pad or paper and then analyzed. A diagnosis of CF is made if the sweat is saltier than normal.
• Sputum test: During a sputum test, the doctor takes a sample of mucus. The sample can confirm the presence of a lung infection. It can also show the types of germs that are present and determine which antibiotics work best to treat them.
• Chest X-ray: A chest X-ray is useful for revealing swelling in the lungs due to blockages in the respiratory passageways.
• CT scan: A CT scan creates detailed images of the body using a combination of X-rays taken from different directions. These images allow your doctor to view internal structures, such as the liver and pancreas, making it easier to assess the extent of organ damage caused by CF.
• Pulmonary function tests (PFTs): PFTs determine whether your lungs are working properly. The tests can help measure how much air can be inhaled or exhaled and how well the lungs transport oxygen to the rest of the body. Any abnormalities in these functions may indicate CF.

Although there’s no cure for CF, there are various treatments available that may help relieve symptoms and reduce the risk of complications.

Medications

• Antibiotics: A doctor may prescribe antibiotics to get rid of a lung infection and prevent a future infection. Antibiotics are usually given as liquids, tablets, or capsules. In more severe cases, injections or infusions of antibiotics can be given intravenously (through a vein).
• Mucus-thinning medications: These make the mucus thinner and less sticky. They also help you cough up the mucus so it leaves the lungs. This significantly improves lung function.
• Nonsteroidal anti-inflammatory drugs (NSAIDs): NSAIDs, such as ibuprofen (Advil), have a limited role as an agent to reduce airway inflammation. The Cystic Fibrosis Foundation suggests the use of high-dose ibuprofen in children ages 6 through 17 with CF who have good lung function. Ibuprofen is not recommended for people with more severe lung function abnormalities or those who are older than age 18.
• Bronchodilators: Bronchodilators relax the muscles around the tubes that carry air to the lungs, which helps increase airflow. You can take this medication through an inhaler or a nebulizer.
• Cystic fibrosis transmembrane conductance regulator (CFTR) modulators: CFTR modulators are a class of drugs that can improve the function of the defective CFTR gene. These drugs represent an important advance in the management of CF because they target the function of the mutated CFTR gene rather than its clinical effects. All patients with CF should undergo CFTR gene studies to determine if they carry one of the mutations approved for CFTR modulator drugs. Most of the available data are in patients less than 12 years old and in patients with mild or moderate CF lung disease.

Surgical procedures

• Bowel surgery: This is an emergency surgery that involves the removal of a section of the bowel. It may be performed to relieve a blockage in the bowels.
• Feeding tube: Cystic fibrosis may interfere with digestion and keep you from absorbing nutrients from food. A feeding tube to supply nutrition can be passed through the nose or surgically inserted directly into the stomach.
• Double lung transplant: When trying to medically manage your CF, you can no longer maintain lung health and function, this procedure can improve the length and quality of life for a person with CF.

Transplant benefits

A lung transplant may be an option to improve and extend your life. However, the CF gene mutation will remain in your body, affecting other organs even after you’ve received new lungs.

There are also a number of things to consider when weighing transplantation as an option. There’s a risk of infection and rejection of the organ, and you will have to take medications that suppress your immune system for the rest of your life.

Chest physical therapy

Chest therapy helps loosen the thick mucus in the lungs, making it easier to cough up. It’s typically performed 1 to 4 times per day.

A common technique involves placing the head over the edge of a bed and clapping with cupped hands along the sides of the chest.

Mechanical devices may also be used to clear mucus. These include:

• a chest clapper, which imitates the effects of clapping with cupped hands along the sides of the chest
• an inflatable vest, which vibrates at a high frequency to help remove chest mucus

Home care

CF can prevent the intestines from absorbing necessary nutrients from food.

If you have CF, you might need more calories per day than people who don’t have the disease. You may also need to take pancreatic enzyme capsules with every meal.

Your doctor may also recommend antacids, multivitamins, and a diet high in fiber and salt.

If you have CF, it’s important to:

• Drink plenty of fluids, because they can help thin the mucus in the lungs.
• Exercise regularly to help loosen mucus in the airways. Walking, biking, and swimming are great options.
• Avoid smoke, pollen, and mold whenever possible. These irritants can make symptoms worse.
• Get influenza and pneumonia vaccinations regularly.

CF cannot be prevented. However, genetic testing should be performed for couples who have CF or have relatives with the disease.

Genetic testing can determine a child’s risk of CF by testing samples of blood or saliva from each parent. Tests can also be performed on you if you’re pregnant and concerned about your baby’s risk.

The outlook for people with CF has improved dramatically in recent years, largely due to advances in treatment. Today, many people with the disease live into their 40s and 50s, and even longer in some cases.

However, there’s no cure for CF, so lung function will steadily decline over time. The resulting damage to the lungs can cause severe breathing problems and other complications.

Next steps

If you or a loved one are believed to have CF, the first steps you should take are to confirm the diagnosis and to become educated on the condition.

A number of tests can be performed to confirm a diagnosis, and your doctor or healthcare professional should be able to discuss how advanced your condition is and what treatment plans will work best.

While there’s no cure for CF, there are some facilities that provide more specialized CF care. Additionally, you will want to make sure to maintain your health and preserve your strength by doing things like:

• practicing strict hygiene to avoid infection
• avoiding people who are sick
• making sure you have adequate nutrition

It takes a whole team of healthcare professionals, a good support system, and the cooperation of employers, schools, and insurers to get people with CF the care they need.

There are a number of online resources and even online or local support groups that can help you or your loved ones cope the with demands of living with — or caring for someone with — CF.

Finding help

There are many organizations that can offer support and resources for living with CF. Below are some available resources: