Bronchiectasis is an irreversible syndrome with typical symptoms of chronic productive cough and recurrent exacerbations and with characteristic findings on cross-sectional imaging of bronchial wall dilation and thickening.



  • Overall annual incidence in U.S. adults estimated to be 29 cases per 100,000
  • Widespread vaccination and improved recognition and treatment of childhood respiratory disease has led to decreased incidence among U.S. children.
    • Incidence may be higher among indigenous or socioeconomically disadvantaged groups.


  • Overall prevalence estimated to be 139 per 100,000 among U.S. adults
  • Higher among women (180 per 100,000) than men (95 per 100,000)
  • Prevalence increases with age: 562 per 100,000 among U.S. seniors aged >65 years
  • Global estimates of prevalence in children ranges from 0.2 to 735 cases per 100,000.
    • Large variability exists among different populations of children.
    • Populations with higher prevalence include children with primary immune deficiencies, chronic aspiration, primary ciliary dyskinesia, airway malformations, and children in low-income countries.

Etiology and Pathophysiology

  • Bronchiectasis is sometimes identified as an isolated pulmonary diagnosis.
  • Often arises as a complication of other inherited or acquired disease states
  • Vicious cycle hypothesis:
    • An initial pulmonary insult causes airway inflammation, dysfunction, and structural disease.
    • Dysfunctional airways are further impaired in their ability to clear infections.
    • A pattern of lung damage/inflammation and progressive airway dysfunction is established, leading to clinical decline.
  • Neutrophil extracellular traps (NETs) and neutrophil elastase are thought to play an important role.
    • Higher levels/activity of these markers correlate with disease activity and may serve as potential therapeutic targets (1).

Risk Factors

Conditions/exposures which cause impaired host defenses, altered tracheobronchial anatomy, airway inflammation, and airway clearance all predispose to development of bronchiectasis.

General Prevention

  • Routine immunization against respiratory infections (pertussis, measles, Haemophilus influenzae type B (HIB), influenza, and Streptococcus pneumonia)
  • Early recognition and treatment of conditions which can lead to bronchiectasis
  • Genetic counseling for patients with inheritable conditions which predispose to bronchiectasis who wish to conceive
  • Smoking cessation

Commonly Associated Conditions

  • Prevalence of conditions associated with bronchiectasis based on U.S. data published in 2017:
    • Pneumonia (68%)
    • GERD (47%)
    • Asthma (29%)
    • Chronic obstructive pulmonary disease (COPD) (20%)
    • Any rheumatologic disease (8%)
    • Immunodeficiency (5%)
    • History of tuberculosis (TB) (4%)
    • Inflammatory bowel disease (3%)
    • Primary ciliary dyskinesia (3%)
  • Other conditions which have been associated with bronchiectasis include:
    • Allergic bronchopulmonary aspergillosis (ABPA)
    • Chronic rhinosinusitis
    • Congenital abnormalities of the airways (e.g., tracheobronchomalacia)
    • α1-Antitrypsin deficiency

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