Chronic cough is defined as a cough that lasts eight weeks or longer in adults. It may be difficult to find the problem that’s causing a chronic cough, the most common causes are postnasal drip, blood pressure medications, smoking, asthma and acid reflux. Chronic cough usually disappears once the underlying problem is treated.

A chronic cough can occur with other signs and symptoms, which may include:

• Frequent throat clearing and sore throat
• A feeling of liquid running down the back of your throat (postnasal drip)
• Hoarseness
• Wheezing and shortness of breath
• Heartburn or a sour taste in your mouth

Causes:

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 may come and go with the seasons, appear after an upper respiratory tract infection, or become worse when you’re exposed to chilly air or certain chemicals or fragrances.

Gastroesophageal reflux disease (GORD). stomach acid flows back into the throat. The constant irritation can lead to chronic coughing.

Infections. A cough can linger long after other symptoms of pneumonia, flu, a cold or other infection of the upper respiratory tract have gone away. A common but under-recognized cause of a chronic cough in adults is pertussis, also known as whooping cough.

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

Chronic bronchitis. This long-standing inflammation of your major airways (bronchial tubes) can cause a cough that brings up coloured sputum.

Less commonly, chronic cough may be caused by:

• Aspiration (food in adults)
• Bronchiectasis (damaged airways)
• Bronchiolitis
• Cystic fibrosis
• Laryngopharyngeal reflux (stomach acid flows up into the throat)
• Lung cancer

Investigation:

These may include X-rays, CT scans, lung function tests (asthma challenge test), blood tests and bronchoscopy.

Treatment:

Determining the cause of a chronic cough is crucial to effective treatment. In many cases, more than one underlying condition may be causing your chronic cough. Treatment may vary from using nasal decongestants, anti-histamine, asthma inhalers, acid-suppressing drugs etc.