Cystic Fibrosis (CF)

What is cystic fibrosis?

Cystic fibrosis (CF) is a genetic disorder (it runs in families) that causes your mucus and sweat glands to behave abnormally. CF causes your mucus to be very thick. This thick, sticky mucus can gather in the lungs and intestines. Over time, it causes permanent damage to these organs.

CF affects all races and ethnic groups but is more common in the white population, especially those with northern European ancestors. As of 2022, the Cystic Fibrosis Foundation estimates that nearly 40,000 children and adults are living with cystic fibrosis in the U.S.

CF is a progressive disease. This means it takes a toll on your body over time. Treatments for CF have improved over the years. This has resulted in a longer life expectancy for those who have CF. Currently, the average life expectancy for a CF patient is mid 40s. However, some patients are living into their 50s.

Symptoms of cystic fibrosis

The symptoms of CF vary from child to child. In most cases, a child will have symptoms before they are a year old. Other times, CF won’t be identified until later — sometimes even not until adulthood.

CF symptoms also vary in severity. One person may have only a few symptoms, while someone else will experience more severe symptoms. Respiratory symptoms are the most common. There are also digestive symptoms and reproductive symptoms. All these symptoms are a result of the thick mucus associated with CF. It blocks air passageways in the lungs. It clogs the digestive system, making it harder for digestive enzymes to pass. In women, a thick cervical mucus may hinder fertility (ability to get pregnant).

Symptoms of CF, as reported by the National Institutes of Health (NIH), can include:

• Very salty-tasting skin
• Recurring sinus infections
• Persistent coughing (with or without phlegm)
• Frequent wheezing or shortness of breath
• Frequent lung infections (pneumonia or bronchitis)
• Persistent diarrhea or constipation
• Bulky, foul-smelling greasy stools (poop)
• Poor growth in children even though appetite is good
• Infertility in woman because of thick mucus covering the cervix
• Infertility in men because they are born without a vas deferens (the tube that delivers sperm from the testes to the penis)

What causes cystic fibrosis?

CF is a genetic disorder. This means it is caused by a defect in a gene. Specifically, this defect occurs on the CFTR gene. The CFTR gene is responsible for producing a protein that controls the movement of salt and water in and out of your body’s cells.

When the CFTR gene is affected, it produces a protein that does not work the way it should. Instead of normal mucus and sweat, the protein causes thick mucus and very salty sweat.

How is cystic fibrosis diagnosed?

The sweat test is considered the most reliable test for diagnosing CF. If you show symptoms of CF, your doctor will order a sweat test. Or, if a blood test or genetic test suggests that you or your child may have CF, a sweat test is typically used to confirm that diagnosis.

A sweat test is simple and painless. During the test, your doctor will apply a chemical to your arm or leg and use electrical stimulation to encourage your sweat glands to begin sweating. They will collect the sweat and send it to the lab. The lab will measure the amount of chloride in the sweat.

If chloride levels are high, that means the salt levels in the sweat are high. High salt levels confirm a CF diagnosis.

Other tests

Once you have been diagnosed with CF, there are other tests your doctor may order. These tests can reveal more information about the severity of your CF and how to treat it.

Other tests include:

• Chest X-ray. A chest X-ray will show if you have scarring in your lungs or swelling of your bronchial tubes. Swelling is a common sign of blockages that can be caused by thick mucus.
• CT scan. A CT scan is primarily used to determine what kind of organ damage CF may have caused.
• Genetic tests. Genetic tests are important because they reveal what type of CFTR defect is causing your CF.
• Sputum test. During this test, your doctor will take a sample of your sputum (mucus that you cough up). This sample can determine whether you have a lung infection. It also will reveal what types of bacteria are causing the infection. This helps your doctor choose an effective antibiotic.

Can cystic fibrosis be prevented or avoided?

CF is a genetic disorder that cannot be prevented. It is passed along when a child inherits the defective gene from both parents.

A child who inherits the defective gene from only one parent is a carrier. When two carriers have a child, there is a 25% chance their child will have CF; there is a 25% chance their child will not have CF and will not be a carrier; there is a 50% chance their child will be a carrier but not have CF.

Cystic fibrosis treatment

There is no cure for CF. The only way to cure or prevent it would involve gene therapy. Researchers continue to explore ways to make this a reality.

Until then, doctors will continue to treat the symptoms of CF to prolong the life expectancy and quality of life for people who have CF. Their treatment plans have improved dramatically over the years.

Lung treatments

There are many ways to treat CF because it varies in severity and symptoms. Mostly, treatment plans for CF aim to prevent and control lung infections. With this being the primary goal, much effort is focused on loosening and removing the thick mucus from the lungs.

Respiratory therapy, physical therapy and exercise, combined with medication, helps reduce the mucus in the lungs. If you have CF, there are several medications your doctor may prescribe. These include:

• Doctors prescribe antibiotics to treat lung infections. Antibiotics can wipe out an active infection and prevent future infections.
• Mucus thinners. Doctors prescribe mucus thinners to make it easier for you to cough up mucus and get it out of your lungs. These are inhalable medicines, meaning you breathe them in.
• Doctors prescribe bronchodilators to help open your airways. These medicines are inhaled to relax the muscles around your airways. They make it easier to breathe by increasing airflow.
• Anti-inflammatories. Doctors prescribe anti-inflammatory drugs to reduce inflammation (swelling) in your airways. This swelling is often caused by ongoing infections. These may be oral medicines (in the form of a pill) or inhalables.

If you have advanced lung disease because of CF, you may also need oxygen therapy as part of your treatment plan.

If your lung disease is severe, a lung transplant may be an option. A lung transplant is a surgical procedure to remove your diseased lung and replace it with a healthy lung from a donor.

Digestive treatments

CF can cause many digestive problems. These problems are not as serious or life threatening as the lung disease associated with CF.

Doctors can usually manage CF-related digestive problems by prescribing nutritional therapy. This typically will include:

• High-calorie diet that is low-fat and high-protein
• High-calorie shakes that offer extra nutrients
• Pancreatic enzymes, an oral supplement that aids digestion
• Dietary supplements of vitamins A, D, E, and K
• Salt supplements to take before exercising

Living with cystic fibrosis

The lifespan of CF patients has increased significantly over the past 3 decades. Thirty years ago, the life expectancy for someone who had CF was less than 20 years. Today, it’s more than twice that (46 years). And some people who have CF live into their 50s.

Living with CF does come with many challenges. Even though treatment options have improved, they are still expensive and can be time consuming. And because care is ongoing (daily), it can become frustrating.

Despite this, most people who have CF are still able to work, go to school, and participate in most typical activities.

Questions to ask your doctor

• How often should we test lung function?
• Are there other treatment options we should try?
• What kinds of side effects can I expect from the medication/treatment?
• Is it okay to have pets in our home?
• If my baby has CF, is breastfeeding an option?

Resources

Cystic Fibrosis Foundation

National Heart, Lung, and Blood Institute: Cystic Fibrosis

National Institutes of Health, Medline Plus: Cystic Fibrosis