Why do I get a cough that won't go away?

A cough outlasting a cold by a week or two is common - airways stay twitchy after infections, sometimes for up to eight weeks, and that post-viral cough fades on its own. A cough past eight weeks is chronic, and three causes explain most of them: upper airway cough syndrome - post-nasal drip tickling the throat, asthma - including cough-variant asthma, where coughing is the only symptom, and reflux reaching the larynx. The NHS advises seeing a provider for a cough lasting more than three weeks, which is the right trigger for the basic workup rather than waiting out eight. Clues to the driver: cough worst at night and after lying down points at drip or reflux; cough with wheezing, or triggered by cold air, exercise, or laughing, points at asthma; cough with heartburn and a sour taste points at reflux. And two medication checks: ACE-inhibitor blood pressure pills cause a dry persistent cough, and smoking keeps any cough alive. The red flags that skip the queue: coughing blood, a new or changing cough in a smoker over 40, cough with unexplained weight loss or drenching night sweats, cough with breathlessness at rest, or cough with chest pain and fever that is not improving. Those get prompt assessment and usually a chest X-ray. For everyone else: a provider visit, the likely-cause checklist, and a trial of treatment aimed at the top suspect. Pymander is a free AI doctor, 24/7 by text. Describe the cough - timing, triggers, what comes with it - and it can help you rank the causes.