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How CF Progresses

Cystic fibrosis (CF) feels a little different for everyone, but everyone experiences progression of CF over time, whether they feel it or not. Progression can occur when the thick mucus building up throughout the body causes inflammation and scarring in many different organs, leading to permanent damage. This damage is often present before it can even be detected by tests, so it's important to understand how progression impacts many different parts of the body over time.

Living with CF

Cycle of Lung Damage

Repeated pulmonary exacerbations cause lung damage

Beginning early, the buildup of thick, sticky mucus in the lungs results in a cycle of infection, inflammation, and more mucus buildup. Pulmonary exacerbations are often a key part of this cycle. This is especially serious because a pulmonary exacerbation means more than just a hospital stay or an extra round of antibiotics. It may cause permanent lung damage that advances disease progression.

Bronchiectasis causes loss of lung function

Chronic inflammation and infection often lead to an extensive and progressive condition called bronchiectasis, which eventually affects virtually all people with CF. Bronchiectasis is a permanent reshaping of the airways that causes them to become loose and scarred. It can make it harder to clear mucus from the lungs and for the airways to move air in and out as a person breathes. As it worsens, the lungs become more damaged, leading to a loss of lung function.

It’s important to promptly treat pulmonary exacerbations to prevent and slow down the progression of bronchiectasis. If left untreated, the cycle of infection and inflammation can result in a permanent loss of lung function.

In CF, permanent lung damage may occur even before it can be detected by lung function tests.

Starting from a young age, people with CF may experience a lung function decline of 1 to 3 percentage points each year on average.

A change in lung function is not always felt

Part of what makes this decline so serious is that some people don’t always feel the change. So someone may lose a lot of lung function before they begin to feel like something is wrong.

Disease progression is universal

CF is different for everyone. But all cases of CF progress over time. Taking a proactive approach to managing CF is the first step toward managing disease.

It’s never too early to have a conversation with a healthcare provider about potential lung damage.

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Having high lung function means that CF is not progressing.

Here's the truth:
Lung function tests don't always detect early lung damage, so lung damage may be present even when lung function is high.


Long-term Digestive Impact

Over time, scarring may result in other conditions

As someone with CF grows up, the same mucus issues that caused digestive problems in childhood may have caused scarring in different digestive organs. This scarring can result in the development of other conditions.

Pancreatic insufficiency

Pancreatic insufficiency (PI) is when the body has a difficult time digesting because enzymes aren’t able to do their job. People with CF who are pancreatic sufficient (PS) are able to digest food normally because they still have pancreatic function. But even those who are PS can show evidence of pancreatic damage and may be at risk for pancreatitis.

85% to 90% of people with CF have pancreatic insufficiency (PI), which is common even at a young age.

Pancreatitis is a serious condition and occurs when enzymes are not able to pass through blocked pancreatic ducts. This causes the pancreas to become inflamed and can result in severe symptoms such as abdomen and back pain, nausea, vomiting, fever, rapid pulse, and weight loss.

The pancreas: cystic fibrosis–related diabetes (CFRD)

Damage caused by thick digestive juices can lead to scarring that makes it more difficult for the pancreas to do its job. As this scarring builds up, many people with CF develop CFRD. This is when the pancreas does not make enough insulin and the body may not be able to properly use the insulin that is produced.

Age percentages

CFRD is a serious condition, but the symptoms are often similar to CF or not noticeable.

According to the American Diabetes Association, annual screening for CFRD should begin by age 10 in all people with CF who do not have CFRD.

It's also important to note that CFRD is different from Type 1 and Type 2 diabetes and therefore is treated differently. If CFRD is left untreated, CF symptoms can worsen, with reduced ability to fight infection, muscle loss, weight loss, liver disease, nerve problems, complications in the kidneys, and a decline in vision.

The liver: cirrhosis

Over time, the thick mucus causes scarring and damage to the liver.

Up to 9% of people with CF develop liver disease, which includes cirrhosis, a buildup of fat in the liver, hepatitis, and other complications.

It sometimes leads to cirrhosis, an advanced stage of liver disease that makes it difficult for blood to travel through the liver. This can result in many complications, including low blood counts, fluid buildup in the abdomen, bleeding in the esophagus, and difficulty breathing.

Liver disease is considered to be one of the most serious health risks associated with CF. There are often no symptoms until the scarring and damage have reached an advanced stage. Care teams regularly monitor liver function in people with CF to check for CF progression in the liver.

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CFRD and cirrhosis
are serious, but not life-threatening complications of CF.

Here's the truth:
CFRD and cirrhosis can be life-threatening, so people with CF are tested regularly for these conditions.


Progression in Other Parts of the Body

CF affects other parts of the body as well. This can be the result of the disease itself or of the different types of medicines used to treat CF.


For people with CF, different factors contribute to low bone density:

  • Bones lose density and don't grow as strong as they should

    Some people may lose bone density more easily. The inflammation caused by frequent lung infections can cause bone tissue to break down.

    For some people, bone development is affected because they may have trouble absorbing enough vitamin D for healthy bone growth. As a result, bones are weak and can fracture more easily.

These factors can contribute to osteoporosis, a disease that can lead to stooped posture, loss of height, and bones that can break easily.

Care teams may suggest using vitamin D supplementation to help reduce inflammation and to promote bone health.

Up to 30% of adults with CF may have low bone mass density.

Care teams begin screening people with CF for bone health at an early age.


About 2% of people with CF between the ages of 25 and 35 have Chronic Kidney Disease (CKD). There are two factors that make adults with CF at risk for CKD. These include progressive cystic fibrosis-related diabetes (CFRD) and treating with certain medications for an extended period of time. Some common symptoms of CKD are itching, muscle cramps, nausea and vomiting, loss of appetite, swelling in feet and ankles, and trouble sleeping.

It’s a good idea to discuss these symptoms with the care team, as they may be a sign of kidney failure.


Medications and treatments are extremely important for people with CF, but over time, those medications may cause side effects. Hearing loss is common in people with CF who have been exposed to certain medications such as aminoglycosides for an extended period of time.

More than 20% of people with CF experience some hearing loss.

It’s important to discuss the progression of hearing loss with the care team so they can help.

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Some effects of CF may have no symptoms.

Many effects of CF are silent at first. For example, lung damage may be occurring before it can be detected by some tests, and many conditions in the digestive system do not have noticeable symptoms early on.

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Some people with CF will develop hearing loss over time.

Hearing loss is common in people with CF who have been exposed to certain medications for an extended period of time.


CF May Cause Depression and Anxiety

As someone with CF gets older, there’s a possibility that other conditions will develop. Both patients and caregivers dedicate so much time and energy to managing and treating CF that sometimes they don’t focus enough on their emotional and mental health.

People living with or caring for someone with CF are at a higher risk of experiencing depression and anxiety for many reasons. Living with CF or caring for someone with CF takes a lot of patience, discipline, and organization. Depression and anxiety can affect both a person living with CF and their caregiver, which may make it hard for them to stay on track with treatment.

About 30% of patients with CF and their caregivers experience depression.

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