Bronchiectasis with or without elevated sweat chloride-1 (BESC1) is a respiratory disease characterized by chronic bronchial inflammation leading to airway dilation. Symptoms include chronic cough, purulent sputum, and recurrent respiratory infections. The severity varies, with some patients having normal respiratory function in adulthood. It is a debilitating condition with features similar to cystic fibrosis but without known causes like autoimmune diseases or ciliary dyskinesia. Clinical manifestations include sub-normal lung function, sinopulmonary infections, chronic productive cough, excessive sputum production, and elevated sweat chloride levels in some cases.