Cystic fibrosis affects how the body moves salt and water in and out of cells. This changes how mucus, sweat, and digestive fluids work.
When these fluids become thick and sticky, they block airways and ducts. This makes it hard to breathe and digest food.
Cystic fibrosis is a genetic condition caused by mutations in the CFTR gene that affect the body’s ability to keep mucus and fluids thin and balanced.
We often think of cystic fibrosis as a lung disease, but it also affects the digestive and reproductive systems. It can cause frequent lung infections, poor growth, and other complications that need daily care and treatment.
Cystic fibrosis (CF) is a genetic condition that interferes with how the body makes and manages mucus, sweat, and digestive fluids. It mainly affects the lungs and digestive system, leading to breathing problems, poor nutrient absorption, and frequent infections.
The severity and symptoms can differ based on the specific genetic changes involved.
Cystic fibrosis occurs when a person inherits changes in both copies of the CFTR gene. This gene controls the movement of salt and water in and out of cells.
When it does not work properly, mucus becomes thick and sticky instead of thin and slippery. This thick mucus clogs airways, traps bacteria, and makes breathing difficult.
It also blocks ducts in the pancreas, preventing digestive enzymes from reaching the intestines. As a result, people with CF often have trouble gaining weight and absorbing nutrients.
CF affects about 35,000 people in the United States. It is a lifelong condition that requires daily management.
Newborn screening and genetic testing help identify CF early, allowing treatment to begin before serious complications develop.
CF impacts several organs, but the lungs and digestive system are most affected. In the lungs, mucus buildup causes chronic coughing, wheezing, and frequent infections.
Over time, this can lead to lung damage and reduced breathing capacity. In the digestive system, blocked pancreatic ducts reduce the flow of enzymes needed to break down food.
This leads to greasy stools, poor growth, and nutrient deficiencies. The liver, sinuses, and reproductive organs can also be affected.
For example, many men with CF experience infertility due to blocked reproductive ducts. Because CF affects fluid balance, people often have salty-tasting skin.
Regular treatments, including airway clearance, medications, and nutritional support, help manage these effects.
We typically describe CF as classic or atypical, depending on how severe the symptoms are and which CFTR mutations are involved.
| Type | Description | Common Features |
|---|---|---|
| Classic CF | The most common and severe form | Lung disease, digestive problems, and male infertility |
| Atypical CF | Milder form, often diagnosed later | Partial lung or digestive symptoms, normal growth |
Classic CF usually appears in infancy or early childhood. Atypical CF may not be recognized until adulthood, as symptoms can be less obvious.
Genetic testing helps confirm which type a person has, guiding treatment decisions and long-term care.
Cystic fibrosis develops when specific genetic changes prevent cells from managing salt and water balance. These changes affect how the CFTR gene works, the structure of the CFTR protein, and how these traits are passed through families.
The CFTR gene (cystic fibrosis transmembrane conductance regulator) provides instructions for making a protein that controls the flow of chloride and water in and out of cells. This process keeps mucus thin and helps organs like the lungs and pancreas work properly.
When the CFTR protein does not function, the body produces thick, sticky mucus. This buildup blocks airways and ducts, leading to breathing and digestion problems.
The CFTR gene sits on chromosome 7. Each of us carries two copies—one from each parent.
A defect in both copies causes cystic fibrosis, while a defect in only one copy makes a person a carrier who does not show symptoms.
More than 2,000 CFTR mutations have been identified, but only a few cause most cases of cystic fibrosis. The most common is ΔF508 (F508del), which deletes one amino acid in the CFTR protein, preventing it from folding correctly.
Other mutations include G542X, N1303K, and G551D, each affecting protein function in different ways. Some stop the protein from forming, while others block its movement to the cell surface or reduce its ability to transport chloride ions.
Researchers group CFTR mutations into six classes based on how they disrupt protein production and function. This classification helps guide treatment, as certain drugs target specific mutation types.
| Mutation Class | Effect on CFTR Protein | Example Mutation |
|---|---|---|
| I | No protein made | G542X |
| II | Misfolded protein | F508del |
| III | Defective channel regulation | G551D |
| IV | Reduced ion flow | R117H |
| V | Reduced protein production | A455E |
| VI | Unstable protein | 4326delTC |
Cystic fibrosis follows an autosomal recessive inheritance pattern. A child must receive two faulty CFTR genes—one from each parent—to develop the disease.
If both parents are carriers, each child has:
Family history plays an important role in identifying risk. Genetic testing can detect carrier status, helping families understand their chances of passing on CFTR mutations.
When one parent has cystic fibrosis and the other is a carrier, each child has a 50% chance of having the disease and a 50% chance of being a carrier.
Cystic fibrosis affects how our bodies handle mucus and salt, leading to problems in the lungs, digestive system, and other organs. The symptoms vary in type and severity, but most relate to breathing issues, nutrient absorption, and other complications caused by thick, sticky mucus.
The lungs are often the most affected organs in cystic fibrosis. Thick mucus builds up in the airways, making it hard for us to breathe and clear germs.
This buildup increases the risk of chronic lung infections, such as bronchitis and pneumonia.
We may experience persistent coughing, sometimes with phlegm, and wheezing due to blocked airways. Over time, these infections can cause lung damage and bronchiectasis, which makes breathing even more difficult.
Sinus infections and nasal polyps are also common. These growths in the nasal passages can make it harder to breathe through the nose.
Many of us also notice shortness of breath during exercise or daily activities, which often worsens as the disease progresses.
| Common Respiratory Symptoms | Description |
|---|---|
| Persistent cough | Often produces thick mucus |
| Wheezing | Caused by narrowed airways |
| Frequent lung infections | Bacterial or viral |
| Sinus infections | Due to mucus buildup |
| Nasal polyps | Soft tissue growths in the sinuses |
Cystic fibrosis affects the pancreas, which makes enzymes needed for digestion. When thick mucus blocks these enzymes, our bodies can’t absorb nutrients properly.
This can lead to malnutrition and poor growth, even when appetite is normal.
We may have frequent, greasy, or bulky stools and bloating because fats and proteins aren’t fully digested. Pancreatic enzyme supplements often help improve nutrient absorption and weight gain.
Infants and children with CF sometimes experience failure to thrive, meaning they gain weight or grow more slowly than expected. Vitamin deficiencies, especially in fat-soluble vitamins (A, D, E, and K), are also common and require supplementation.
People with cystic fibrosis often have salty-tasting skin, which comes from higher salt levels in sweat. This is one reason the sweat test is a key diagnostic tool.
We may develop clubbing, where the fingertips and toes become rounder and wider due to long-term low oxygen levels. Chronic sinus problems, rectal prolapse, and male infertility can also occur.
Some of us experience fatigue or reduced exercise tolerance because our lungs and digestive systems work harder than normal. These symptoms can vary widely, but together they reflect how cystic fibrosis affects multiple systems in the body.
People with cystic fibrosis often experience long-term problems in the lungs, digestive system, and other organs. We see frequent infections, poor nutrient absorption, and hormonal or reproductive challenges that require ongoing care and monitoring.
Thick mucus in the airways traps bacteria and makes it hard to clear the germs. Over time, this leads to repeated infections such as bronchitis and pneumonia.
These infections cause coughing, shortness of breath, and gradual lung damage. We often find Pseudomonas aeruginosa and Staphylococcus aureus as common bacteria in the lungs.
Chronic infection triggers inflammation, which thickens airway walls and reduces airflow. Regular airway clearance, inhaled antibiotics, and anti-inflammatory treatments help slow this process.
When lung damage becomes severe, patients may develop bronchiectasis, where the airways widen and lose elasticity. This makes mucus clearance even harder and increases infection risk.
Close monitoring and early treatment are key to maintaining lung function.
Cystic fibrosis blocks the ducts in the pancreas, preventing digestive enzymes from reaching the intestines. This causes poor absorption of fat and protein, leading to weight loss, bloating, and greasy stools.
We treat this with pancreatic enzyme replacement and high-calorie diets. Thick secretions can also block bile ducts, leading to liver disease.
Over time, this may cause scarring, known as cirrhosis. Signs include jaundice, an enlarged liver, and abnormal liver function tests.
We monitor liver health closely through blood tests and imaging. In advanced cases, medications that thin bile or liver transplantation may be needed.
Good nutrition and early detection reduce the risk of severe liver problems.
Damage to the pancreas can also affect insulin production, leading to cystic fibrosis-related diabetes (CFRD). This condition combines features of both type 1 and type 2 diabetes.
We screen for it regularly because early control helps preserve lung and nutritional health. Typical symptoms include increased thirst, weight loss, and fatigue.
Management involves insulin therapy and careful meal planning. Oral diabetes drugs are less effective for CFRD.
People with cystic fibrosis also face a higher risk of osteoporosis due to poor nutrient absorption and chronic inflammation.
Low bone density increases fracture risk. We recommend vitamin D and calcium supplements, weight-bearing exercise, and bone density scans to protect bone strength.
Most men with cystic fibrosis are infertile because the vas deferens, the tube that carries sperm, does not develop properly. This condition, called congenital bilateral absence of the vas deferens (CBAVD), prevents sperm from reaching semen but does not affect sexual function.
Assisted reproductive techniques, such as sperm retrieval and in vitro fertilization, allow many men to have biological children. Genetic counseling helps couples understand inheritance risks.
Women with cystic fibrosis may also face fertility challenges from thick cervical mucus and poor nutrition. With proper care, many can conceive safely, but pregnancy requires close medical supervision to protect both mother and baby.
We diagnose cystic fibrosis (CF) using a combination of laboratory tests and clinical evaluation. The main tools include newborn screening, sweat chloride testing, and genetic testing to confirm CFTR gene mutations.
Early and accurate diagnosis allows us to begin treatment promptly and manage symptoms before serious complications develop.
Most babies in the United States undergo newborn screening for CF shortly after birth. This test measures the level of immunoreactive trypsinogen (IRT) in the blood.
High IRT levels may suggest CF, but do not confirm it. When screening results are abnormal, we perform a sweat chloride test.
This test measures the amount of salt (chloride) in a baby’s sweat. People with CF typically have chloride levels above 60 mmol/L.
Sweat testing is noninvasive and remains the gold standard for confirming CF. To ensure accuracy, it should be done at a certified CF center.
If results fall in the intermediate range (30–59 mmol/L), additional testing and repeat sweat tests may be needed.
| Sweat Chloride Result | Interpretation |
|---|---|
| <30 mmol/L | CF unlikely |
| 30–59 mmol/L | Borderline |
| ≥60 mmol/L | CF confirmed |
Genetic testing identifies mutations in the CFTR gene, which cause CF. More than 2,000 CFTR mutations exist, but only some lead to disease.
Testing can confirm a diagnosis when sweat test results are unclear. We use genetic testing to find two disease-causing mutations, one from each parent.
If both are present, the diagnosis is confirmed. In some cases, only one mutation is detected, requiring further evaluation.
Carrier screening helps identify people who carry one faulty CFTR gene. Couples with a family history of CF often undergo this testing before or during pregnancy.
If both partners are carriers, each child has a 25% chance of inheriting CF.
Some people develop atypical or late-onset CF, where symptoms are mild or appear in adulthood. These cases often involve mutations that only partially affect CFTR function.
Diagnosis can be challenging because sweat chloride levels may be normal or borderline. In such cases, we rely on a combination of genetic analysis, nasal potential difference testing, and clinical findings such as chronic sinus infections or pancreatitis.
Atypical CF may affect only one organ system, like the lungs or reproductive tract.
We manage cystic fibrosis (CF) by focusing on keeping the lungs clear, treating infections, and maintaining proper nutrition. Our approach combines physical airway clearance, targeted medications, and enzyme replacement to help the body absorb nutrients and reduce complications.
Airway clearance helps remove thick mucus from the lungs and prevents infection. We often use chest physical therapy, which involves rhythmic clapping or vibration on the chest and back to loosen mucus.
Devices such as a high-frequency chest wall oscillation vest or positive expiratory pressure (PEP) devices make this process easier. These tools help move mucus upward so it can be coughed out.
We may also use nebulizers to deliver inhaled medications like saline or bronchodilators before airway clearance. This thins mucus and opens airways.
Regular airway clearance, done several times a day, is key to preserving lung function and reducing hospitalizations.
CF treatment includes several medications that target different problems. Antibiotics treat or prevent lung infections and can be inhaled, oral, or intravenous, depending on severity.
Inhaled medications such as bronchodilators relax airway muscles, while mucolytics like dornase alfa break down mucus. CFTR modulators improve how the defective CFTR protein works.
Examples include:
| Medication | Brand Name | Use |
|---|---|---|
| Ivacaftor | Kalydeco | For certain CFTR mutations |
| Lumacaftor/Ivacaftor | Orkambi | For people with two F508del mutations |
| Elexacaftor/Tezacaftor/Ivacaftor | Trikafta | For at least one F508del mutation |
These drugs help improve lung function and weight gain in many patients. We adjust treatments based on age, symptoms, and genetic type.
Because CF affects digestion, we use pancreatic enzyme replacement therapy to help absorb fats and nutrients. These enzymes are taken with meals and snacks.
We also recommend high-calorie, high-fat diets to meet energy needs. Patients often need vitamin supplements, especially fat-soluble vitamins A, D, E, and K.
In some cases, we add nutritional shakes or tube feeding to support growth and maintain a healthy weight. Proper nutrition strengthens the immune system and supports lung health.
We continue to see steady progress in cystic fibrosis (CF) care through focused research, new therapies, and strong community support. Advances in genetics, clinical trials, and patient-centered programs have improved both survival and quality of life for people living with CF.
Cystic fibrosis research focuses on understanding how mutations in the CFTR gene cause thick, sticky mucus that damages the lungs and other organs. Scientists study how to correct or replace the faulty CFTR protein so it can move chloride properly across cell membranes.
Since the 1950s, CF research has led to major discoveries, including the identification of the CFTR gene and the development of CFTR modulators. These medicines target the underlying cause rather than just the symptoms.
Organizations such as the Cystic Fibrosis Foundation (CFF) and the National Heart, Lung, and Blood Institute (NHLBI) fund studies on infection control, gene therapy, and drug development. Research also explores how to manage complications like pancreatic insufficiency and liver disease.
| Focus Area | Research Goal |
|---|---|
| Gene therapy | Correct or replace defective CFTR genes |
| Infection control | Prevent chronic lung infections |
| Nutrition studies | Improve absorption and growth outcomes |
CF clinical trials test new medicines and approaches that can improve lung function, reduce infections, and extend life expectancy. Many trials evaluate CFTR modulators such as ivacaftor, lumacaftor, tezacaftor, and elexacaftor, which treat specific gene mutations.
We also see trials exploring triple-combination therapies that help more people benefit from CFTR correction. Other studies assess inhaled antibiotics, anti-inflammatory drugs, and treatments that thin mucus or repair tissue damage.
Participation in clinical trials gives patients early access to promising therapies while helping researchers collect data on safety and effectiveness. The Therapeutics Development Network, supported by the CFF, coordinates many of these studies across accredited care centers.
New research directions include mRNA-based treatments and gene-editing tools like CRISPR, which may one day allow us to fix the faulty gene directly.
Living with CF requires daily management and emotional strength. The Cystic Fibrosis Foundation provides resources, education, and access to specialized care.
The CFF accredits more than 130 care centers across the United States. These centers offer multidisciplinary teams including pulmonologists, dietitians, and respiratory therapists.
Patients work with these teams to create individualized care plans. These plans help balance health goals with daily life.
Support networks connect families through events and online communities. Educational programs are also available.
Financial and mental health resources are offered to help reduce the stress of long-term treatment.
Cystic fibrosis is a complex genetic condition that affects multiple organs—especially the lungs and digestive system—due to the body’s inability to regulate salt and water balance. Recognizing how CFTR gene mutations disrupt mucus production helps explain the chronic respiratory infections, digestive challenges, and long-term complications many patients face. With early diagnosis, consistent treatment, and the support of a specialized care team, individuals with CF can manage symptoms, prevent complications, and maintain a higher quality of life. Advances in genetic testing, CFTR modulators, and comprehensive care programs continue to expand the possibilities for long-term health and improved daily functioning. Understanding the disease empowers patients and families to make informed choices and take proactive steps toward better breathing and overall wellness.
Get the dedicated pulmonary support your family deserves.
At Gwinnett Pulmonary & Sleep, our board-certified pulmonologists provide comprehensive care for cystic fibrosis and other complex lung conditions. From diagnosis to long-term management, our team offers advanced testing, personalized treatment plans, and compassionate guidance every step of the way.
Book your appointment today at gwinnettlung.com or call 770-995-0630 to schedule your visit.
Plugin powered by Kapsule Corp
