CF affects multiple systems in the body, and symptoms can vary widely from person to person. Some people may show signs shortly after birth, while others are diagnosed later in childhood or even adulthood. No two people with CF experience the exact same symptoms, and the type of CFTR gene mutation a person has can influence how severe their symptoms are, how early they appear, and how they respond to treatment.

Understanding the signs of CF is key to early intervention, and with the right care, people with CF can manage many symptoms and lead longer, more fulfilling lives.

The Lungs

The lungs are the organ most affected by CF. Thick, sticky mucus clogs the airways and traps bacteria, leading to repeated infections and inflammation. Over time, this cycle can cause bronchiectasis, where airways become widened and damaged, resulting in scarring, further mucus build-up, and progressive loss of lung function.

Common lung and respiratory symptoms include:

• Frequent coughing, often with thick mucus

• Repeated chest infections

• Wheezing or shortness of breath

• Chronic sinus infections and nasal polyps, causing congestion or reduced sense of smell

Breathing becomes increasingly difficult without effective treatment, and in severe cases, lung damage can lead to respiratory failure.

The Digestive System and Pancreas

CF can block the pancreas, preventing digestive enzymes from reaching the intestines. Without these enzymes, the body struggles to absorb nutrients properly, leading to malnutrition and digestive problems such as:

• Poor growth and weight gain

• Frequent, greasy, or bulky stools

• Abdominal pain and bloating

• Bowel obstructions (including meconium ileus in newborns)

CF can also affect insulin production, sometimes causing CF-related diabetes. Managing digestive issues usually involves pancreatic enzyme replacement therapy, acid blockers, and vitamin supplements to support nutrition and overall health.

The Liver

CF can cause cystic fibrosis-related liver disease (CFLD) when thick mucus blocks bile ducts, leading to liver damage. CFLD is most commonly diagnosed in children and teenagers but can develop in adults.

Possible signs of liver involvement include:

• Enlarged liver (hepatomegaly) or spleen (splenomegaly)

• Jaundice (yellowing of skin and eyes)

• Fluid buildup in the abdomen (ascites)

• Fatigue and poor growth

Not everyone with CF develops liver problems, and for many, any changes are mild. Regular blood tests and scans help monitor liver health, and treatments can support liver function. In rare cases, a liver transplant may be necessary.

The Sinuses and Nasal Passages

Chronic sinus infections, nasal congestion, and growth of nasal polyps are common in CF. These issues can worsen breathing difficulties and cause discomfort.

The Reproductive System

CF affects fertility, particularly in males. Most men with CF are born without vas deferens, the tube that carries sperm, making natural conception extremely unlikely. Assisted reproductive techniques, such as sperm retrieval and IVF, can help.

Women with CF may experience reduced fertility due to thick cervical mucus or other factors, though many can conceive with medical support and careful planning.

Bones, Joints, and Fatigue

CF can impact bones and joints in the following ways:

• Bone thinning and osteoporosis: Caused by malabsorption of vitamin D and calcium, chronic inflammation, delayed puberty, reduced activity, and long-term corticosteroid use.

• Joint pain: From inflammation, CF-related arthritis, or treatment side effects.

• Fatigue and low energy: Chronic infections, inflammation, malnutrition, and the effort of daily treatments can make everyday tasks tiring.

Symptoms in Babies and Children

In Australia, most babies with CF are diagnosed through newborn screening. Early signs to watch for include:

• Poor weight gain or failure to thrive

• Persistent wet cough and frequent respiratory infections

• Greasy, bulky bowel movements

• Intestinal blockage (meconium ileus) at birth

Aging with CF

As people with CF live longer, their needs change over time. Regular check-ups help monitor lung health, nutrition, and overall wellbeing. Adjusting treatments, staying active, and eating a balanced diet can help manage symptoms. Small daily changes, like planning activities around energy levels or seasonal changes, also make a difference.

Why This Matters

CF affects the entire body in complex ways. Its relentless nature means damage accumulates over time, making daily management essential. While treatments improve symptoms and slow progression, ongoing research and funding are critical to finding a cure.