All are the above are true.
Key Impacts on the Lungs:
Thick Mucus Production: The defective CFTR protein causes mucus to become thick and sticky, which traps bacteria and hinders the lungs' ability to clear germs.
Chronic Infections & Inflammation: Bacteria trapped in the mucus lead to long-term (chronic) infections, resulting in inflammation, damage to the airways, and further mucus production.
Bronchiectasis: The airways become permanently dilated and damaged due to the constant inflammation and infection.
Respiratory Failure: The primary cause of death in CF patients is progressive, severe lung damage leading to respiratory failure.
Physical Changes: Other complications include narrowed airways, mucus plugs, coughing up blood, pneumothorax (collapsed lung), and nasal polyps.