The Vicious Cycle of Bronchiectasis

Living with a Lung Disease

When a patient is diagnosed with bronchiectasis, a plan for long-term monitoring and care is critical. Some patients experience daily and burdensome symptoms that worsen upon exacerbation.

Bronchiectasis moves in a vicious cycle with the potential to cause increasing amounts of damage to airways. Untreated, this vicious cycle of infection, inflammation, and injury often results in progressive symptoms and loss of lung function, chronic lung infection, poor pulmonary function tests and decreased activity and quality of life.

Because bronchiectasis is frequently secondary to these other conditions, it can be difficult to diagnose and to determine the proper course of treatment. Both doctors and patients must learn to recognize the cycle associated with bronchiectasis so that symptoms may be addressed and additional damage prevented.

Understanding the Vicious Cycle of Bronchiectasis

Bronchiectasis progresses according to a cycle first proposed by P. J. Cole and known as Cole’s theory. The cycle follows a distinct pattern recognizable by characteristics associated with each phase:


The trigger, often some type of lung infection which may be facilitated by mucus buildup, introduces bacteria or viruses into the lungs


The body releases immune cells and compounds in response to the infection

Mucus Production

Mucus production increases as the infection progresses

Bacterial Growth

Uncleared mucus causes increased bacteria growth and spreading

Airway Thickening

Airway walls thicken and become less elastic, preventing mucus clearance

This cycle continues to repeat itself and compound the damage to lung tissue unless symptoms are properly diagnosed and addressed with a comprehensive treatment plan including bronchial hygiene techniques such as Airway Clearance Therapy. Since bronchiectasis is often associated with conditions like COPD and cystic fibrosis, testing patients with these diseases for lung problems should be a top priority for physicians.

The Problem of Recurring Lung Infections

Recurring lung infections from bronchiectasis may be caused by different pathogens or may be chronic due to mucus failing to be cleared from the lungs. Patients with bronchiectasis have been shown to harbor more bacteria and other pathogens in the lungs and have more inflammatory markers in their bodies. Exacerbations are made worse by and can be more frequent during infections, a complication indicative of increased inflammation and progressive tissue damage.

Once bronchiectasis has been triggered, it becomes difficult for sufferers to avoid subsequent infections. Any bacterial or viral lung infection can cause more inflammation, leading to more damage and making bronchiectasis increasingly harder to treat. Infections are also responsible for causing exacerbations, acute periods during which symptoms become more severe and can have a serious impact on a patient’s quality of life.

Chronic Inflammation puts patients with bronchiectasis at higher risk for:

  • Influenza
  • Moraxella catarrhalis
  • MRSA
  • Pseudomonas aeruginosa
  • Staphylococcus aureus
  • Streptococcus pneumoniae
  • Viral infections

Any occurrence of these infections perpetuates the inflammatory cycle, causing additional lung damage. The potential for progressive deterioration makes monitoring for infections and administering prompt treatment all the more important.