Bronchiectasis is a chronic airway disease characterized by irreversible bronchial dilatation and substantial clinical heterogeneity. Accumulating evidence from large international observational cohorts has highlighted wide variation in the features of this disease and unmet clinical needs. The treatable traits-based approach has emerged as a means to prioritize identifiable and clinically actionable problems over traditional diagnostic labels. In this review, we summarize the reported prevalence of major treatable traits across large cohorts and describe notable regional differences, alongside the ongoing absence of data relating to behavioral and environmental traits. We further update the treatable traits framework based on recent guideline recommendations, clarifying the strength of evidence supporting the interventions available. We also review selected molecular mechanisms relevant to key treatable traits. Despite growing interest, the use of treatable traits in routine practice is restricted by ambiguous terminology, insufficient prospective data, and inadequate evidence for many therapies. However, the fundamental constraint for implementation is not insufficient characteristic identification, but rather the attempt to manage a complicated and non-linear disease system with a static checklist. Future research should emphasize standardized definitions and real-world longitudinal studies, and develop practical tools to help clinicians determine which traits should be addressed first. Such efforts may support transparent, individualized, and adaptive decision-making in bronchiectasis.

Bronchiectasis is a clinical syndrome characterized by dilated and thickened airways paired with clinical symptoms, most commonly a chronic suppurative cough that characteristically exacerbates. The disease can have burdensome symptoms that reduce quality of life. Pharmacologic treatments to date have been few and limited largely to antibiotic therapies. In recent years, bronchiectasis has been reconceived as a primary inflammatory disease, and drug development has since shifted to identify anti-inflammatory and immunomodulatory drugs.

Kartagener syndrome, a variant of primary ciliary dyskinesia, is defined by chronic sinusitis, bronchiectasis, and situs inversus. While recurrent infections are seen, a combination of thromboembolic disease, pulmonary mycetoma, cardiac dysfunction, and serological evidence of autoimmune disorders is very uncommon.

Allergic bronchopulmonary aspergillosis/mycosis (ABPA/ABPM) is an immunologically mediated pulmonary disorder triggered by the colonization of filamentous fungi in the airways of patients with asthma or cystic fibrosis, leading to type I and III hypersensitivity responses, eosinophilic mucus plug formation, and central bronchiectasis. Over the past decade, advances in basic and clinical research have substantially reshaped the understanding and management of this disease. Although Aspergillus species, particularly Aspergillus fumigatus, remain the predominant causative fungi, epidemiological studies have identified Schizophyllum commune as an important and previously underrecognized pathogen responsible for ABPM. A major breakthrough in elucidating disease pathophysiology is the recognition of eosinophil extracellular trap cell death as a central mechanism driving highly viscous mucus impaction. Diagnostic criteria with improved accuracy and standardized treatment protocols have been established through randomized controlled trials, culminating in the 2024 revision of the International Society for Human and Animal Mycology guidelines. However, significant unmet needs remain. Despite high initial response rates to corticosteroids or azole antifungals, nearly half of patients fail to achieve remission. Predictors of treatment failure include heightened A. fumigatus-specific sensitization and radiological evidence of eosinophilic mucus impaction. Biologic agents targeting type 2 inflammation have emerged as promising options for difficult-to-treat disease, although their efficacy in acute ABPA is still uncertain. Frequent exacerbations also pose a major challenge, and the potential benefits of maintenance inhaled antifungals and environmental interventions are under investigation. Collectively, advances in pathophysiology, diagnostics, and therapeutics are transforming ABPA/ABPM management, yet substantial gaps persist in improving long-term outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT04442269.