What are Common Complications of Cystic Fibrosis?

Reviewed by: HU Medical Review Board | Last reviewed: September 2019

Cystic fibrosis (CF) can cause a wide range of complications that vary depending on the genetic profile of that person’s particular CF mutation, age, and gender.

Almost everyone with CF experiences significant respiratory and gastrointestinal complications eventually, but the age when these begin, and the severity, can be quite different from person to person.

What are some of the causes of complications in cystic fibrosis?

Respiratory and gastrointestinal complications are often caused directly by the thick, sticky mucus generated because the body can’t process the cystic fibrosis transmembrane conductance regulator (CFTR) protein properly. The CFTR protein helps our cells move the chloride ion, an element in salt, to a cell’s surface. Without chloride, water isn’t attracted to the cell surface, which causes thick, sticky mucus to clog airways and ducts throughout the body.

However, some complications are the downstream result of the disease or treatment. And, people with CF who have had organ transplants are more likely to experience complications.

Severity of complications

If the body can’t move the mucus out of the airways, then it also can’t move out the bacteria and viruses that cause cold, flu and pneumonia. This same mucus in the pancreas, intestines, and liver prevents the body from absorbing nutrients properly, causing malnutrition, slow growth in children, and underweight in adults.

Complications can be mild at times, and severe at others (called an exacerbation). Some people with CF experience few complications until well into adulthood, while some children with CF can be very sick from birth.

Sticking to the daily respiratory treatments recommended by your medical team helps maintain lung function in all ages of people with CF and lung growth in children. Healthier lungs mean some complications of CF may be delayed or even avoided.

Most common cystic fibrosis complications by age

Complications from CF can differ greatly by age and the type of CF mutation. For example, meconium ileus, or a failure to pass the first stool, is a condition only seen in newborns. Anxiety and depression were seen in less than 10% of children in 2017 but nearly 50% of adults with CF.1

Many complications do not begin to occur until the person with CF ages into adulthood.

Virtually all people with CF experience persistent lung infections, though this can vary widely from case to case. Some people with rare CFTR mutations may not develop serious lung infections well into adulthood.

Other common complications (in roughly the order of most frequently experienced) include:

Here is how often some common complications were found in people with CF in 2017, according to the CF Foundation’s Patient Registry Annual Data Report.

Common complications of CF

Symptoms DescriptionPercent under 18Percent over 18
ArthritisJoint pain affects large joints, such as the knees, ankles, wrists, elbows and shoulders..5%6.2%
Bone diseaseOsteoporosis and osteopenia1.9%26%
CF-related diabetesOccurs most often in adults with CF. Partially as a result of long-term inflammation of the pancreas.5.3%31%
GastrointestinalDistal intestinal obstructive syndrome (DIOS)2.0%2.6%
Gastrointestinal Gastroesophageal reflex disease (GERD)36.1%39.6%
Gastrointestinal History of intestinal or colon surgery, usually to repair perforation from stool blockage.3.6%1.5%
Hearing loss Hearing difficulties and deafness can result from long-term use and high doses of certain antibiotics and long-term sinus infections.1.3%3.1%
Hypertension High blood pressure0.4%5.7%
Liver disease Both cirrhosis and non-cirrhosis5.8%7.5%
Mental health Depression and anxiety7.7%47.4%
Respiratory Allergic bronchopulmonary aspergillosis (ABPA)2.6%7.5%
Respiratory Asthma30.5%33.4%
Respiratory Hemoptysis or coughing up blood0.8%5.9%
Respiratory Sinus disease22.7%53.8%

Complications by mutation class

Thanks to DNA testing, doctors can now group cystic fibrosis into five distinct classes with genetic variables. Many complications do not change much between classes, but some do.

For instance, CF-related diabetes, liver disease, and distal intestinal obstructive syndrome (DIOS) are more common among those in Class I, II or III. These people also tend to have more severe CF. By comparison, pancreatitis is seen more often in people in class IV and V. Sinus disease, anxiety and depression do not seem to change greatly between classes.1

In 2017, the Cystic Fibrosis Foundation analyzed the medical data of 23,106 people with CF in their Patient Registry Annual Data Report and found that:

  • 85.3% were part of Classes I, II and III
  • 14.7% were part of Classes IV and V1

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