What causes persistent cough?

A cough can continue when the airways remain inflamed after an infection, react to asthma or allergies, or are irritated by smoke, dust, or post-nasal mucus. Reflux can trigger coughing even without obvious heartburn, and some medicines can contribute. Lung cancer, non-small cell lung cancer, small cell lung cancer, and mesothelioma can present with a persistent cough, but most persistent coughs have other explanations. The sound of a cough cannot identify its cause.

Record how long the cough has lasted, whether it is dry or brings up mucus, and what triggers it. Mention smoking, workplace dust or asbestos exposure, allergies, reflux, fever, breathlessness, chest pain, and medicines. A clinician may listen to your chest and decide whether imaging, breathing tests, or other assessment is appropriate. Avoid smoke and seek advice before using cough medicines if you have other conditions or take regular medicines.

Arrange a medical review for a cough that persists, changes, or repeatedly returns. Seek urgent help for coughing blood, severe breathlessness, blue lips, sudden chest pain, confusion, fainting, or rapidly worsening symptoms. These red flags need prompt assessment and do not depend on whether cancer is likely.

Ask what causes fit your cough and exposure history, whether you need a chest examination or tests, and which symptoms should prompt urgent care. If a scan shows an abnormal area, ask what it may represent and whether further testing is needed.