Cough lasting three weeks: what to do

Coughing may continue after a cold or acute bronchitis because the airways remain sensitive. Allergic rhinitis can cause drainage that irritates the throat, while asthma may show as cough, wheeze or tightness. Acid reflux can provoke coughing after meals or when lying down. Bronchiectasis may produce repeated chest infections or regular mucus. Chronic cough is a description of persistence, not a single diagnosis.

Record when you cough, whether mucus is present, and links with meals, exercise, sleep, dust or cold air. Drink enough to avoid a dry throat, avoid smoking and ask a pharmacist about suitable symptom relief. Continue prescribed medicines as directed, but do not add antibiotics or change an inhaler without advice. A clinician may review your chest, medicines, nasal symptoms and reflux symptoms before deciding whether tests are needed.

Seek urgent care for severe breathing difficulty, coughing blood, new confusion, fainting, blue lips or sudden chest pain. Request prompt medical advice for persistent fever, unexplained weight loss, night sweats, worsening breathlessness, repeated chest infections or a cough that is rapidly changing. People with significant lung disease or reduced immunity should contact their care team sooner.

Could this be post-infectious irritation, asthma, reflux or nasal drainage? What details should I track? Do my medicines or smoking exposure contribute, and what examination or testing would help clarify the cause?