I appreciate the responses by Mr Tan Jun You (TCM gaining traction worldwide, April 22) and Mr Amos Wu Pom Hin (Unfair to knock TCM because of one mistake, April 22) to my letter (What is TCM diagnosis based on?, April 18) regarding traditional Chinese medicine (TCM) practices.

I am familiar with the ancient texts on which TCM is based, such as The Yellow Emperor's Classic Of Internal Medicine and the Treatise On Febrile Diseases Caused By Cold by Zhang Zhongjing of the Han dynasty, among other books.

There was not much difference between TCM and Western medicine in the time of Hippocrates in the 5th century BC.

TCM had its postulates of body organs categorised under five elements - metal, wood, water, fire and earth - and diseases caused by the imbalance of the mysterious yin and yang.

The Greeks had their four elements - fire, air, earth and water - and believed that diseases were caused by the conflict of "humours" of the body.

The difference is Western medicine did not just stop at that stage, but kept on renewing, reinventing and progressing, whereas TCM theories have remained essentially unchanged for more than 2,000 years.

Ong Siew Chey (Dr)