What mainstream medicine says:
A dry cough is one in which no phlegm is produced in the respiratory tract, unlike a wet cough.
But knowing if a cough is dry or wet is not enough to help diagnose its underlying cause, said Dr Kenneth Chan, a consultant respiratory physician and intensivist at Gleneagles Medical Centre and Mount Elizabeth Novena Specialist Centre.
Instead, the doctor has to check for other symptoms.
Dr Chan said that common causes of a persistent dry cough may include a recent viral infection, such as the common cold or influenza; and gastroesophageal acid reflux disease, in which stomach contents flow upwards into the foodpipe and lead to throat irritation and very mild asthma.
In more severe forms of asthma, the cough is usually accompanied by symptoms of chest tightness, breathlessness and wheezing.
A dry cough can also signify more serious conditions, such as pneumonia, tuberculosis and lung cancer. Therefore, it is important to visit a doctor if a person's cough does not go away after a few weeks, he added.
The treatment of a dry cough is aimed at its cause. For instance, acid-suppressing medicine will control coughs arising from gastroesophageal acid reflux disease.
Dr Chan suggests taking a spoonful of honey to help control a cough, but stressed that "this is not as important as finding out the cause of the cough".
"Honey acts as a cough suppressant," he said.
"In addition, it soothes the throat on contact and has antioxidant and antimicrobial properties."
This article was first published on June 18, 2015.
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