‘久咳’ literally combines ‘久’ (jiǔ), meaning 'long time' or 'prolonged', and ‘咳’ (ké), meaning 'cough'. Together, it refers to a persistent or chronic cough that lasts for several weeks—typically longer than eight weeks in clinical terms. Unlike acute coughs caused by colds or allergies, 久咳 often signals an underlying health issue such as bronchitis, asthma, postnasal drip, or even gastroesophageal reflux.

This term is commonly used in medical contexts, patient self-reports, and health discussions. It carries a slightly formal or clinical tone and is rarely used in casual conversation without reference to symptoms or treatment. You’ll see it on clinic intake forms, in doctor–patient dialogue, or in traditional Chinese medicine (TCM) diagnoses where duration is key to differentiating syndromes like 'lung yin deficiency' or 'phlegm-damp accumulation'.