Bronchiectasis.

Bronchiectasis refers to abnormal dilatation of the bronchi. Airway dilatation can lead to failure of mucus clearance and increased risk of infection. Pathophysiological mechanisms of bronchiectasis include persistent bacterial infections, dysregulated immune responses, impaired mucociliary clearance and airway obstruction. These mechanisms can interact and self-perpetuate, leading over time to impaired lung function. Patients commonly present with productive cough and recurrent chest infections, and the diagnosis of bronchiectasis is based on clinical symptoms and radiological findings. Bronchiectasis can be the result of several different underlying disorders, and identifying the aetiology is crucial to guide management. Treatment is directed at reducing the frequency of exacerbations, improving quality of life and preventing disease progression. Although no therapy is licensed for bronchiectasis by regulatory agencies, evidence supports the effectiveness of airway clearance techniques, antibiotics and mucolytic agents, such as inhaled isotonic or hypertonic saline, in some patients. Bronchiectasis is a disabling disease with an increasing prevalence and can affect individuals of any age. A major challenge is the application of emerging phenotyping and endotyping techniques to identify the patient populations who would most benefit from a specific treatment, with the goal of better targeting existing and emerging treatments and achieving better outcomes.