What Is Cystic Fibrosis?

Cystic fibrosis (CF) is an inherited disease in which the body makes very thick, sticky mucus. The mucus causes problems in the lungs, pancreas, and other organs.

People with cystic fibrosis (SIS-tik fye-BROH-sis) get lung infections often. Over time, they have more trouble breathing. They also have digestive problems that make it hard to gain weight.

What Are the Signs & Symptoms of Cystic Fibrosis?

CF can cause symptoms soon after a baby is born. The first sign a baby might have cystic fibrosis is an intestinal blockage called meconium ileus. Other kids don't have symptoms until later on. Cystic fibrosis can be mild or severe, depending on the person.

Symptoms of cystic fibrosis include:

  • lung infections or pneumonia 
  • wheezing
  • coughing with thick mucus
  • bulky, greasy bowel movements
  • constipation or diarrhea
  • trouble gaining weight or poor height growth
  • very salty sweat

Some kids also might have nasal polyps (small growths of tissue inside the nose), frequent sinus infections, and tiredness.

How Is Cystic Fibrosis Diagnosed?

Newborn screening tests catch most cases of CF. If the screening test is positive, or if a child has cystic fibrosis symptoms, doctors do a painless sweat test. They collect sweat from an area of skin (usually the forearm) to see how much chloride (a chemical in salt) is in it. People with CF have higher levels of chloride.

Most children with CF are diagnosed by the time they're 2 years old. But someone with a mild form may not be diagnosed until they are a teen.

How Is Cystic Fibrosis Treated?

Kids with CF will have it all their lives. Doctors use different medicines depending on a child's needs. But all people with CF need to:

  • Loosen and clear mucus. There are different ways to do this. The doctor might recommend a child:
    • get regular exercise
    • use an inhaler or nebulizer
    • do breathing exercises and cough on purpose
    • wear a therapy vest that shakes the chest
    • have chest physical therapy (when a parent or trained person bangs gently on the chest or back)
  • Prevent or fight lung infections. Washing hands well and often, avoiding people who are sick, and staying at least 6 feet away from others with CF can help prevent infections. Taking preventive antibiotics also can help.
  • Take enzymes. Most kids with CF need enzymes to help them digest food and get nutrients from it.
  • Eat a high-calorie diet and take vitamin supplements, when needed.

What Causes Cystic Fibrosis?

Cystic fibrosis is caused by a change (mutation) in the gene that makes cystic fibrosis transmembrane regulator (CFTR) protein. To have CF, a baby must get two copies of the CF gene, one from each parent.

What Happens in Cystic Fibrosis?

In CF, the body makes abnormal CFTR protein or none at all. Without normal CFTR protein, the cells lining the pathways (tubes) inside some organs make thick, sticky mucus rather than the normal thin, watery kind.

Thick mucus can trap bacteria in the lungs, leading to infection, inflammation, and breathing problems. Mucus also can block the path where digestive enzymes flow between the pancreas and the intestines. This makes it hard for a child to digest food and get the vitamins and nutrients they need from it.

Thick mucus can also affect the liver, the sweat glands, and the reproductive organs.

How Can Parents Help?

To help your child:

  • Follow the treatment plan. Help your child stay as healthy as possible. Give medicines as directed, serve high-calorie meals and snacks, and follow instructions for clearing chest mucus.
  • Offer encouragement. Help your child find pastimes to enjoy, like art, music, reading, or learning to cook. It's important for kids with CF to get exercise, so also look for ways your child can stay physically active. Maybe you can do some of them together.
  • Turn to the care team. Your child's care team can offer practical tips on living with CF, and information about clinical trials, support groups, and new therapies.
  • Learn all you can about CF. Experts are always working on new treatments to help people with CF have a better quality of life and live longer. Online, turn to resources like the Cystic Fibrosis Foundation website.
  • Teach self-care as your child gets older. Start early to help your child understand and manage CF. Encourage an older child or teen to handle some parts of their health care, like disinfecting equipment or asking questions at doctor visits. Ask the care team about ways you can help your child get ready for things like going to college or getting a job. Learning about cystic fibrosis and its care helps kids and teens become confident adults managing a chronic health condition.
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Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.