Cystic Fibrosis

Medically Reviewed by Poonam Sachdev on April 28, 2022
5 min read

Cystic fibrosis (CF) is a genetic disorder, which means you get if from your parents at birth. It affects the way your body makes mucus, a substance that helps your organs and systems work. Mucus should be thin and slippery, but when you have CF, it becomes thick and glue-like. This blocks tubes and ducts throughout your body.

Over time, this thick mucus builds up inside your airways. This makes it hard to breathe. The mucus traps germs and leads to infections. It can also cause severe lung damage like cysts (fluid-filled sacs) and fibrosis (scar tissue). That’s how CF got its name.

More than 30,000 people in the U.S. live with cystic fibrosis. Doctors diagnose about 1,000 new cases each year.

People with CF can have symptoms including:

  • Trouble with bowel movements or frequent, greasy stools
  • Wheezing  or trouble breathing
  • Frequent lung infections
  • Infertility, especially in men
  • Trouble growing or gaining weight
  • Skin that tastes very salty

Cystic fibrosis is caused by a change, or mutation, in a gene called CFTR (cystic fibrosis transmembrane conductance regulator). This gene controls the flow of salt and fluids in and out of your cells. If the CFTR gene doesn’t work the way it should, a sticky mucus builds up in your body.

To get CF, you have to inherit the mutated copy of the gene from both of your parents. Ninety percent of those with affected have at least one copy of the F508del mutation.

If you inherit only one copy, you won’t have any symptoms, but you will be a carrier of the disease. That means there’s a chance you could pass it to your children.

About 10 million Americans are CF carriers. Every time two CF carriers have a baby, there’s a 25% (1 in 4) chance that their baby will be born with CF.

Early diagnosis means early treatment and better health later in life. Every state in the U.S. tests newborns for cystic fibrosis using one or more of these three tests:

  • Blood test. This test checks the levels of immunoreactive trypsinogen (IRT). People with CF have higher levels of it in their blood.
  • DNA test. This looks for mutations to the CFTR gene.
  • Sweat test. It measures the salt in your sweat. Higher than normal results suggest CF.

Some people who weren’t tested at birth aren’t diagnosed with CF until they become adults. Your doctor might give you DNA or sweat tests if you have symptoms of the disease.

There’s no cure for cystic fibrosis, but medications and other therapies can ease symptoms.

Medications. Your doctor may give you drugs to open your airways, thin mucus, prevent infections, and help your body get nutrients from food. These include:

  • Antibiotics. They can prevent or treat lung infections and help your lungs work better. You might get them as pills, in an inhaler, or in a shot.
  • Anti-inflammatory medicines. These include ibuprofen and corticosteroids.
  • Bronchodilators. You’ll get these from an inhaler. They’ll relax and open your airways.
  • Mucus thinners. They’ll help you get the gunk out of your airways. You’ll get them from an inhaler.
  • CFTR modulators. These help CFTR work like it should. They can make your lungs work better and help you gain weight.
  • Combination therapy. The new medication elexacaftor/ivacaftor/tezacaftor (Trikafta) combines three CFTR modulators to target the CFTR protein and make it work for efficiently.

Airway clearance techniques. These can help get rid of mucus. You might try:

  • Chest therapy or percussion. This involves tapping or clapping on your chest or back to clear mucus from your lungs. Someone else does this for you.
  • Oscillating devices. You breathe into a special device that oscillates, or vibrates, your airways. This loosens mucus and makes it easier to cough up. You can wear an oscillating chest vest instead.

Physical therapy for CF. This includes breathing exercises designed to push air between layers of mucus and your chest wall. They make it easier to cough up the gunk and ease blocked airways. Some common exercises include:

  • Autogenic drainage. To do this, you breathe out hard, or huff. This moves mucus from your smaller airways to the central airways and makes it easier to get out.
  • Active cycle of breathing. This controls your breath and relaxes the upper chest and shoulders, which can help clear mucus and prevent airway blockages. You breathe in deeply, hold it, and then huff for different lengths of time.

The lungs aren’t the only part of your body CF damages. Cystic fibrosis also affects the following organs:

  • Pancreas. The thick mucus caused by CF blocks ducts in your pancreas. This stops proteins that break down your food, called digestive enzymes, from reaching your intestine. As a result, your body has a hard time getting the nutrients it needs. Over time, this can also lead to diabetes.
  • Liver. If the tubes that remove bile get clogged, your liver gets inflamed. This can lead to severe scarring called cirrhosis.
  • Small intestine. Because it can be hard to break down high-acid foods that come from your stomach, the lining of the small intestine can wear away.
  • Large intestine. The thick fluid in your stomach can make your poop large and harder to pass. This can lead to blockages. In some cases, your intestine may also start to fold in on itself like an accordion, a condition called intussusception.
  • Bladder. Chronic or long-lasting coughing weakens your bladder muscles. Almost 65% of women with CF have stress incontinence. This means that you leak a little pee when you cough, sneeze, laugh, or lift something. Though it’s more common in women, men can have it, too.
  • Kidneys. Some people with CF get kidney stones. These small, hard globs of minerals can cause nausea, vomiting, and pain. If you don’t treat them, you could get a kidney infection.
  • Reproductive organs. Excess mucus affects fertility in men and women. Most men with CF have problems with the tubes that move sperm, called the vasa deferentia. Women with CF have very thick cervical mucus, which can make it harder for a sperm to fertilize an egg.
  • Other parts of the body. CF can also lead to muscle weakness and thinning bones, or osteoporosis.  Because it upsets the balance of minerals in your blood, it can also cause low blood pressure, fatigue, a fast heart rate, and a general feeling of weakness.

Although CF is a severe condition that needs daily care, there are many ways to treat it, and there’s been a great improvement in those treatments over the years. People who have CF now can expect to live a much longer life than those who had it in the past.