What are the causes of a chronic cough?

There are a number of causes of chronic cough. Some of the more common causes include:

Postnasal drip. When your nose or sinuses produce extra mucus, it can drip down the back of your throat and trigger your cough reflex.

Asthma. An asthma-related cough can be variable and change with the seasons, appear after an infection of the upper respiratory tract, or become worse when you’re exposed to cold air, certain chemicals or fragrances.

Gastroesophageal reflux disease (GERD). Reflux occurs when stomach acid flows back into your food pipe (esophagus). The constant irritation can lead to chronic coughing, which in turn can worsen the relux, making this a vicious cycle.

Infections. A lingering cough post a viral or bacterial infection can occur.

Blood pressure drugs. Angiotensin-converting enzyme (ACE) inhibitors, commonly prescribed for high blood pressure and heart failure, can cause chronic cough in some people.

Chronic bronchitis. This is an inflammation of your major airways (bronchial tubes) can cause a cough that brings up sputum. Most people with chronic bronchitis are current or former smokers and may have other smoking related lung problems.

Laryngeal hypersensitivity. This can occur when the back of your throat becomes sensitive to things like cold air, talking, funny odours, or certain chemicals.