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What are Common Symptoms of Cystic Fibrosis?

The type and severity of cystic fibrosis (CF) symptoms can differ widely from person to person. With 1,700 known genetic variations, doctors are still learning which symptoms are tied to particular versions of CF.

Types of cystic fibrosis symptoms and severity vary by age

Some people with CF have few gastrointestinal problems in childhood other than acid reflux, yet go on to develop frequent gas, constipation, and pancreatitis as adults. Some children with CF get frequent lung infections like pneumonia or have trouble growing, while others remain mostly healthy. Some adults with CF develop CF-related diabetes or liver disease while others do not.

Doctors do know that some symptoms of CF are more common in childhood and some are more frequent in older teens and adults. Unusually severe lung (pulmonary) symptoms are called exacerbations.

The most common CF symptoms that appear in children and adults can be different depending on age and the subtype of CF the person has. Below are listed the symptoms most likely to appear for babies, children and adults:

What are the most common cystic fibrosis symptoms in infants?

Symptoms in infants (under age 1)1-7

Symptom Description
Salty skin or sweat Salt is not processed properly by the sweat glands so sweat is very salty.
Meconium ileus A baby’s first stool that is so thick and sticky it blocks the intestines. This is the first clue that a baby has CF in 10-20% of cases.4
Poor growth, malnutrition Failure to gain weight, even with a healthy appetite. Having little energy or losing weight. Wanting to eat more or less than normal.
Unusual bowel movements Frequent diarrhea; large and greasy stools, foul-smelling stools, or constipation.
Gastrointestinal issues Abnormal stools, acid reflux.


What are the most common cystic fibrosis symptoms in children?

Symptoms in children (over age 1)1-7

Symptom Description
Respiratory symptoms Chronic cough; wheezing/shortness of breath; frequent colds, lung infections and sinus infections; nasal polyps, collapsed lung.
Poor growth, malnutrition Failure to gain weight, even with a healthy appetite. Having little energy or losing weight. Wanting to eat more or less than normal. Delayed puberty.
Sinus symptoms Nasal polyps, sinus infections.
Gastrointestinal issues Gas, stomachache, GERD, jaundice, severe abdominal pain, frequent diarrhea; large and greasy stools, foul-smelling stools, constipation, and DIOS.
Mental health issues Depression and anxiety


Other less common symptoms that children make experience include clubbing of the fingers and toes, fever and night sweats, muscle and joint pain.

What are the most common cystic fibrosis symptoms in teens and adults?

As people with CF live longer, some symptoms become more likely, usually as a result of long-term complications of their body trying to process CF’s thick, sticky mucus.1-7

Symptoms in teens & adults

Symptom Description
Respiratory symptoms Chronic cough; wheezing/shortness of breath; frequent colds, lung infections and sinus infections; nasal polyps, collapsed lung, bronchiectasis (enlargement of passageways in the lungs).
Gastrointestinal symptoms Malnutrition, low weight, eating fatigue, pancreatic issues, liver disease, rectal prolapse, GERD, gas, constipation, gallstones, dehydration.
Pancreatic symptoms CF-related diabetes (CFRD) may occur when the pancreas is unable to release insulin due to the clogging from thick mucus.
Male reproductive issues Infertility
Female urogenital issues Infertility, thrush/yeast infections, stress incontinence, and menstrual irregularities.
Hearing loss Due to long-term chronic sinus infections and prolonged use of large doses of antibiotics.
Mental health issues Depression and anxiety
Bone disease Osteoporosis and osteopenia may be caused by long-term malabsorption of nutrients and use of steroids can lead to weak bones.6
Clubbing of the fingertips and toes Due to poor lung function, fingernails or toenails become rounded or flattened at the ends.
Arthritis2 Common symptoms of arthritis are joint pain and swelling.


Daily CF symptoms versus exacerbations

When daily symptoms become so severe that hospitalization is required, it is called an exacerbation. The most common exacerbation in people with CF are pulmonary (lung) infections. Exacerbations are usually treated with a strong course of antibiotics that lasts two or more weeks. Sometimes the course of treatment may be finished at home. Exacerbations occur most often in people with CF between the ages of 15 and 30.7

Written by: Jessica Johns Pool | Last reviewed: September 2019
  1. Stanford Health Care. Symptoms of Adult Cystic Fibrosis. Available at: https://stanfordhealthcare.org/medical-conditions/chest-lungs-and-airways/adult-cystic-fibrosis/symptoms.html. Accessed 4/20/2019.
  2. University of Michigan. Cystic Fibrosis (Adults). Available at: https://www.uofmhealth.org/conditions-treatments/pulmonary/cystic-fibrosis. Accessed 4/20/2019.
  3. Children’s National Health System. Pediatric Cystic Fibrosis. Available at: https://childrensnational.org/choose-childrens/conditions-and-treatments/airway-lungs/cystic-fibrosis. Accessed 4/20/2019.
  4. National Organization for Rare Disorders. Cystic Fibrosis. Available at: https://rarediseases.org/rare-diseases/cystic-fibrosis. Accessed 4/20/19.
  5. National Heart, Lung, and Blood Institute. Cystic Fibrosis. Available at: https://www.nhlbi.nih.gov/health-topics/cystic-fibrosis. Accessed 4/20/2019.
  6. Cystic Fibrosis Foundation. Nutrition: Bone Health and Cystic Fibrosis. Available at: https://www.cff.org/PDF-Archive/Bone-Health-and-Cystic-Fibrosis. Accessed 4/20/19.
  7. Cystic Fibrosis Foundation. Patient Registry Annual Data Report 2017. Available at: https://www.cff.org/Search.aspx?topic=230. Accessed 4/22/2019.