Respiratory System Symptoms

Cystic fibrosis is a genetic condition caused by mutations in the cystic fibrosis conductance transmembrane regulator (CFTR) gene. The mutation leads to the production of abnormal CFTR protein or no CFTR protein at all. This disrupts the flow of salts and water across cell membranes, causing a buildup of thick, sticky mucus in the lungs, kidneys, pancreas, and other organs. The abnormal buildup of mucus is mainly responsible for the symptoms of CF.

Lung involvement

The accumulation of thick mucus in the lungs is a typical feature of CF, causing lung infections and other respiratory system symptoms. Thick, sticky mucus in the lungs creates an environment that is favorable for the growth of bacteria. A healthy lung is capable of clearing the infection, but the thick mucus in CF provides a breeding ground for infection-causing agents to persist, leading to chronic lung infections or pneumonia.

The most common bacteria associated with CF lung infections is Pseudomonas aeruginosa. Although usually treatable with antibiotics, some strains of P. aeruginosa have evolved to become increasingly resistant to most antibiotics. Persistent infection with bacteria such as P. aeruginosa can lead to further inflammatory damage in the lungs.

Thickened sticky mucus can also clog the airways in the lungs, hindering airflow and causing breathing problems and bronchitis (inflammation in the tubes that carry air to the lungs). This can result in symptoms such as wheezing (shortness of breath) and a persistent cough.

Blood flow through the arteries can be blocked in mucus-clogged lungs, causing an increase in blood pressure and resulting in pulmonary hypertension and further deteriorating lung function. High blood pressure also may lead to heart problems in the long term.

As CF progresses, the risk of developing severe respiratory complications such as pneumothorax (collapsed lung) increases considerably.

Upper respiratory tract involvement

Sinusitis (inflammation of sinus cavities in the nose) is common in children with CF.

The lining of the nose can also become inflamed in CF patients, causing small non-cancerous growths called nasal polyps. These may form in the sinuses and the nostrils, causing breathing difficulties. Medication can be used to treat nasal polyps, and in some instances, doctors may need to remove them surgically.

Treatment of respiratory system symptoms

Several treatment options are available to lower and manage the respiratory symptoms of CF. Anti-inflammatory medications and inhaled bronchodilators (which cause airways to open wider) can aid in breathing. Likewise, antibiotics to clear lung infections can help preserve lung function.

Advanced therapies such as CFTR modulators that target the underlying cause of CF also can clear the airways, ease breathing, and improve patients’ quality of life.

Physiotherapy may help loosen the mucus in the lungs, making it easier to cough it out.

Respiratory symptoms and lifestyle changes

Lifestyle changes, such as quitting smoking and increasing fluid intake, can help manage the respiratory system symptoms of CF. Regular physical exercise to support lung function, and practicing breathing techniques that help loosen the mucus can help alleviate these symptoms.

Nutrition plays a vital role in improving quality of life for people with CF. Eating a healthy diet, and including supplements in the diet to facilitate nutrient absorption, is critical for CF patients.

Nutritional changes should be made only after consulting with a doctor and following that recommendation. In addition, any exercise and physical activity should be performed under the guidance of a doctor and experienced physiotherapist.


Last updated: July 28, 2021


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