A cough that follows a cold usually settles within a few weeks. When it lingers beyond three weeks, or keeps returning, it is worth asking what is actually driving it.

Common causes of a lingering cough

  • Post-infection airway irritation: airways can remain sensitive for weeks after a viral or chest infection.
  • Asthma, including cough-predominant asthma: cough may be the main symptom, sometimes with little wheeze.
  • Post-nasal drip or chronic sinus problems: mucus draining down the throat.
  • Acid reflux: acid or irritants affecting the throat and airway.
  • Smoking, smoke or dust exposure: including chronic bronchitis and COPD.
  • Medicines: some blood-pressure tablets in the ACE-inhibitor group can cause a dry cough — never stop them without medical advice.
  • Tuberculosis and other chronic infections: especially with fever, night sweats or weight loss.
  • Other conditions: heart or lung disease needing specific assessment.

Warning signs that need a prompt review

  • Coughing blood or blood-streaked sputum
  • Fever, night sweats or unexplained weight loss
  • Breathlessness, chest pain or noisy breathing
  • Hoarseness lasting weeks, or difficulty swallowing

What to bring to the appointment

A timeline of when the cough began, what makes it better or worse, whether it is dry or productive, your medicines (including blood-pressure tablets), smoking and exposure history, and any previous chest imaging or test reports. Do not take leftover antibiotics or steroids on your own — the cause matters, and the wrong treatment can mask the picture.

Patient sources: WHO — Chronic respiratory diseases ↗ and WHO — Tuberculosis ↗

Frequently asked questions

When is a cough considered chronic?

A cough lasting more than eight weeks in adults is commonly called chronic, and one lasting three to eight weeks is often called subacute. Either deserves review if it is not clearly improving.

Do I need a chest X-ray for a long-lasting cough?

It is often considered, especially if there are warning signs or risk factors. Whether it is needed depends on your history and examination.

This article is general education and does not replace an examination, diagnosis or treatment plan.