We divide it into three by duration. Under three weeks is acute, three to eight weeks is subacute, and eight weeks or more we regard as chronic.

Three weeks may still be within the post-infectious recovery process. It is common for the state of the airway being sensitised after a cold to continue for a few weeks.

However, once it goes past eight weeks we do not regard it as simple post-infectious cough and look for the cause. Post-nasal drip, acid reflux and asthma are the three most common.

There are cases requiring confirmation regardless of duration. If blood-stained sputum, fever, weight loss, night sweats or breathlessness is accompanying it, please be sure to tell us at the consultation. If examination indicates it, we will arrange testing such as a chest X-ray.