Cystic fibrosis (CF) is a chronic, inherited disease that primarily affects the lungs and digestive system. It is caused by changes (mutations) in a gene that controls how salt and water move in and out of cells. These gene changes lead to thick, sticky mucus that can clog airways, trap bacteria, and block ducts in organs such as the pancreas.
Cystic fibrosis is present from birth and affects children and adults. Because it is genetic, it tends to appear in families where both parents carry a CF-related gene mutation, even if they do not have symptoms themselves.
Common symptoms
Cystic fibrosis symptoms vary widely, even among people with the same gene changes, but most affect the lungs and digestive system.
Respiratory issues include chronic cough with thick mucus, recurrent lung infections such as bronchitis or pneumonia, and wheezing or shortness of breath.
Digestive problems include poor weight gain despite good appetite, frequent bulky or greasy stools, and abdominal pain, bloating, or constipation. Other signs include frequent sinus infections, nasal polyps, and possible male infertility. Formal testing is essential to confirm CF and prevent misdiagnosis.
Diagnosis
Cystic fibrosis is often identified early in life, but some people are diagnosed later in childhood or adulthood. Key diagnostic approaches include:
- Newborn screening: Many regions routinely screen newborns for CF using blood tests that look for markers suggesting the disease
- Sweat test: Measures the amount of salt (chloride) in sweat; higher-than-normal levels strongly suggest CF
- Genetic testing: Identifies mutations in the CFTR gene, which confirm the diagnosis and may guide treatment choices
Together, these tests help clinicians confirm CF, determine disease severity, and tailor follow-up care.
Risk factors and causes
Cystic fibrosis is caused by mutations in the CFTR gene, which disrupt the CFTR protein responsible for regulating chloride and water movement across cell membranes. When this protein malfunctions, mucus becomes thick and sticky, leading to blockages and progressive organ damage, especially in the lungs and digestive system.
CF risk is primarily genetic, according to the Cystic Fibrosis Foundation (CFF). It follows an autosomal recessive pattern: a child must inherit faulty CFTR genes from both parents. If both parents are carriers, each pregnancy has a 25% chance of CF, 50% chance of a carrier child, and 25% chance of an unaffected child.
There are no environmental or behavioral causes in non-carriers, but factors like tobacco smoke, pollution, and untreated infections can worsen symptoms and speed lung damage in people with CF.
Living with CF
With today’s treatments, many people with cystic fibrosis are living longer, fuller lives. The key is consistent, proactive management. Effective CF care focuses on a daily routine that keeps lungs clear, digestion on track, and overall health as strong as possible.
According to the CFF, it is possible to manage CF by staying active and sticking to a special diet.
Common treatment options
Cystic fibrosis care focuses on preserving lung function, supporting nutrition, and managing complications. Airway clearance techniques—such as chest physiotherapy, percussion, or mechanical vests—help loosen and remove thick mucus from the lungs. Inhaled bronchodilators, mucus thinners, and antibiotics improve airflow and prevent or treat infections, while oral or IV antibiotics address lung infections promptly.
Digestive support often includes pancreatic enzyme capsules with meals to improve fat and protein digestion. Your doctor may recommend a high-calorie, nutrient-dense diet and supplementation with vitamins A, D, E, and K to help maintain weight and support growth. Additional treatments may be needed for constipation, intestinal blockages, or CF-related diabetes.
For individuals with eligible CFTR mutations, CFTR modulator therapies directly target the defective protein, improving lung function, reducing exacerbations, and enhancing overall health. Some patients may require surgery for complications, including sinus surgery, feeding tube placement, bowel surgery, central line insertion, or lung transplantation in advanced disease.
These treatments are delivered by a multidisciplinary team, including pulmonologists, surgeons, gastroenterologists, and nutrition specialists.
To learn more or contact a surgeon at WashU Medicine, please call:
- Pediatric surgery: 314-454-6022
- Thoracic surgery: 314-362-7260