The common causes in chronic cough are generally three.

Post-nasal drip is the most common. Secretions from the nose and sinuses run down the back of the throat and irritate the airway. A feeling of something caught in the throat and frequent throat-clearing go with it.

Acid reflux is also common, and as cough alone can appear without heartburn, people often do not realise it. It worsens after eating or on lying down.

Cough-variant asthma is asthma in which only a dry cough appears, without wheezing. It worsens in the small hours and in cold air.

Besides these, there are cases where smoking or some blood pressure medications (ACE inhibitors) are the cause. If you are taking blood pressure medication, please tell us. In this case changing the medication sometimes resolves it.