Coughing is a protective reflex that clears the airways. After a viral infection it is normal for a cough to linger for one to two weeks. When it continues beyond three weeks, it is described as a persistent or chronic cough and deserves a closer look.
Common causes of a long-lasting cough
Airway conditions such as asthma, post-infective airway irritation, allergic rhinitis with post-nasal drip, acid reflux, chronic bronchitis and, in some settings, tuberculosis are among the frequent causes. Certain blood pressure medicines can also cause a dry cough.
Warning signs that need prompt evaluation
Coughing up blood, unexplained weight loss, fever lasting more than a week, night sweats, increasing breathlessness or chest pain should be evaluated without delay.
What an evaluation involves
A pulmonologist takes a detailed history, examines the chest and may advise appropriate tests such as a chest X-ray, sputum testing or lung function testing depending on the clinical picture. Treatment is directed at the underlying cause rather than the cough alone.