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Cystic Fibrosis

Medically reviewed by: Larissa Hirsch, MD

What Is CF?

Cystic fibrosis (say: SIS-tik fi-BRO-sus), or CF, is a disease that causes the body to make thick, sticky mucus (say: MYOO-kus). This causes problems in two major areas: the lungs and the digestive system.

What Happens in CF?

Healthy lungs make mucus, which protects the airways and makes it easier to breathe. To make normal mucus, which is thin and watery, the body needs a special protein. This protein is defective in cystic fibrosis. So the body makes thick, sticky mucus instead, which can clog the lungs. This creates a place where bacteria can easily grow — and bacteria cause infections.

And it's not only the airways and lungs that are affected by cystic fibrosis. Mucus-producing cells line the digestive system, including the stomach, intestines, liver, pancreas, and reproductive organs. The pancreas makes enzymes that help digest food and hormones that help absorb sugar. Thick mucus in the pancreas can make it hard for people to digest food and get all the vitamins and nutrients they need.

What Causes CF?

CF is an inherited disease, which means it's passed down from parent to child. Someone who has CF was born with it. Maybe you've heard someone say, "It's in your genes." Genes make up the blueprint each of your cells follows to make you a unique individual.

People with CF got the disease because their moms and dads each had a gene for CF. You need two CF genes (one from mom and one from dad) to have cystic fibrosis.

Cystic fibrosis can be mild or severe, depending on the person.

How Is CF Diagnosed?

Although someone with cystic fibrosis is born with it, it isn't always found at birth. It may take a while for symptoms to develop. Doctors may suspect CF if a kid coughs a lot and gets a lot of lung infections. A kid also might have big, bulky bowel movements (poop) or may not gain weight as expected.

To know for sure, the doctors can do a simple test that doesn't hurt. Kids with CF have more salt in their sweat than other kids. So by testing a sample of sweat to check how much salt is in it, doctors can see if a person has CF.

How Is CF Treated?

The aim of CF treatment is to keep the lungs clear of mucus and free of infection. It's also important for someone with CF to eat well.

A kid with CF will work with a medical team, including doctors, nurses, dietitians, and respiratory therapists. A respiratory therapist knows a lot about breathing and how the lungs work. They can teach a kid with CF to do special breathing exercises that help get rid of extra mucus. Breathing treatments also help by adding moisture and delivering medicine into the lungs.

To help prevent or fight lung infections, wash your hands well and often and try to avoid people who are sick. Taking preventive antibiotics, which kill bacteria, also can help. Sometimes, kids with CF can get respiratory infections and may need to stay at the hospital for a while. The good news is that newer medicines are more effective and help kids with CF recover faster.

Kids with cystic fibrosis have to work a little harder to breathe, and this burns more calories. So it's important that they get enough to eat. Even a kid with CF who eats healthy foods and gets plenty of calories may still have trouble growing and gaining weight.

The problem is that the pancreas can't deliver the enzymes needed to break down protein and fat in food. Kids with CF may have more frequent bowel movements (poop) because they're not absorbing the protein and fat they eat. Most kids with CF take medicine that helps digest food but may also need to take a vitamin and mineral supplement.

A dietitian can help kids figure out which foods to eat and provide special recipes packed with nutrients and calories. Along with eating right, it's important for kids with CF to get regular exercise to make their lungs as strong as they can be.

Living With CF

Kids who have CF have to take care of themselves, but thanks to improved treatment, they can go to school and do regular stuff, just like other kids. Meanwhile, researchers are working on even better treatments and hoping that one day there will be a cure.

  • What's It Like to Have Cystic Fibrosis?

    What's It Like to Have Cystic Fibrosis?

    People who have cystic fibrosis need to take special care of their lungs. Find out what it's like to be a kid who has this condition.

Medically reviewed by: Larissa Hirsch, MD
Date reviewed: July 2020