In the present issue of the European Respiratory Review, CERVERI and BRUSASCO [1] propose that ‘‘the view that chronic mucus hypersecretion plays a secondary role in the pathogenesis of COPD should be abandoned and instead, mucolytic agents should be considered as a treatment option’’[1]. In the same series, BALSAMO et al.[2] provide an overview of currently available mucoactive drugs, and DECRAMER and JANSSENS [3] examine the evidence for proposing long-term treatment with so-called ‘‘mucolytics’’(eg N-acetylcysteine and carbocysteine) in patients with chronic obstructive pulmonary disease (COPD).

Mucus hypersecretion has long been limited to chronic cough and sputum production. Thus, epidemiological studies that have focused on the potential impact of chronic cough and sputum production in COPD called it chronic mucus hypersecretion [4, 5]. In this editorial, we examine the evidence suggesting that mucus hypersecretion is a major feature in all COPD patients, including those without cough and sputum production. We suggest that mucus hypersecretion should be a therapeutic target in all COPD subjects (ie subjects with and without chronic cough and sputum production) and discuss some aspects of the development of drugs targeting mucus hypersecretion in COPD.