Introduction to TCM

Basics of TCM

  • Yin-Yang | Five Elements

Zang-Fu Theories

  • Zang Organs | Fu Organs

Classification of Antineoplastic Herbal Medicines

Characteristics of Herbal Medicines


  • By Auscultation & Olfaction
  • By Inspection


Theories of Channels (Meridians) and Collaterals

Reference: A Modern View of the Immune System

Differentiation of Syndromes

  • 8 Principles
  • 6 Channels 4 Stages
  • Syndromes of Zang-Fu Organs


  • Exogenous | Pestilential
  • Pathogenic Factors
  • Emotional

Materia Medica

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The Theory of Channels and Collaterals

The theory of channels and collaterals is an important component of the theoretical system in traditional Chinese medicine. It covers the physiological functions and pathological changes of the channels and collaterals, their interrelations with the zang-fu organs, and is essential in guiding clinical practice, especially acupuncture treatment.

The Formation and Functions of Channels and Collaterals

1. Channels and Collaterals System

The system of channels and collaterals constitutes the twelve regular channels, the eight extra channels, the fifteen collaterals, the twelve divergent channels, the musculo-tendinous and cutaneous regions of the twelve regular channels.

2. Channels and Collaterals Functions

(1) Physiologically, the channels and collaterals are considered to be a series of connecting passages through which qi and blood circulate to regulate the functions of the zang-fu organs, tissues, and sense organs. These passages also conduct the sensations and reactions (deqi) of acupuncture treatment.

The five zang and six fu organs, four limbs, nine orifices, skin muscles, vessels, and tendons, although having their respective physiological functions, also maintain the harmonization and uniqueness of interior, exterior, upper, and lower parts of the body as a united and organic entity. This interconnection and organic combination relies upon the function of the channels and collaterals system.

All the tissues and organs of the human body need the nourishment of qi and blood in order to keep their normal physiological activities. The distribution and circulation of qi and blood throughout the body to nourish the zang-fu, tissues, and organs and to resist exogenous pathological factors depends on the transportation and conduction of the channels and collaterals. As the Lingshu records:

The channels and collaterals are the passages through which blood and qi flow to nourish yin and yang, to moisten tendons and bones, and to lubricate the joints.

(2) Pathologically, channels and collaterals are the pathways through which the exogenous pathological factors are transmitted and their channels reflected. In the Suwen it is noted:

When pathogenic factors invade the skin and the pores are open they enter the collaterals. When the collaterals become full, the pathogenic factors will move into the channels. When the channels are full, the pathogenic factors transmit to and reside in the zang and fu organs.

The interior and exterior, upper and lower parts of the body form an integrated entity through the connecting network of channels and collaterals. So under pathological conditions every part of the body will affect the rest via the channels and collaterals. The channels and collaterals are not only the passages of disease transmission, but can also reflect pathological changes. Namely, the diseases of the zang-fu organs can be reflected on the body surface, especially in certain areas or at certain points, through the transmission of channels and collaterals.

(3) In diagnosis, channels and collaterals have certain running courses that connect with the zang-fu organs. They also reflect pathological changes on the body surface. Therefore clinical diagnosis can be made according to symptoms that are related to those courses and their respective zang-fu organs.

(4) In treatment, the theory of channels and collaterals is extensively used in clinical treatment for different branches of traditional Chinese medicine. Treatments using traditional medicinal herbs are based on their main actions vis-a-vis related zang-fu organs and channels. In the practice of acupuncture, the theory of channels and collaterals is the basis of all treatment and clinical practice. Point selection and prescription combinations are all made on this basis. By stimulating a certain point or area on the body surface the physiological functions of the channels and collaterals are aroused. This action is achieved by propagating sensation through the channels. Without this sensation it is hard to achieve a therapeutic effect.

Related Subjects

The Twelve Regular Channels
Pathways, Conjunctures, Exterior-Interior Relationships and the Order of Qi Flow in the Channels
Eight Extra Channels
The Fifteen Collaterals
The Twelve Divergent Channels
The Twelve Musculotendinous Regions of the Regular Channels
The Twelve Cutaneous Regions of the Regular Channels

Traditional Chinese Medicine pages by Raymond Cheng, PhD DPA FRSA FRSPH

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With over 3000 years of experience, Traditional Chinese Medicine (TCM) has remain one of the many fascinating areas in ancient Chinese culture. First known to be documented in the Yellow Emperor's Canon of Medicine, TCM is believed to have been practised in as early as 475 to 221 B.C. The field of working knowledge of TCM stretches from anything related to general healthcare practice to the philosophy of the mind, the logic of life, religion, and even to as far as cosmology and astronumerology. This is why in order to thoroughly understand the concepts behind TCM, one must be comprehensive in learning and embracing the Chinese culture as a whole.

Just as Douglas Hoff put it when he explained about accupuncture, "The systems of TCM uses the concepts of elements and meridians and are completely immersed in the Asian cosmology which takes shape through the religions." The meridian-brain mechanism, the fundamental working concept of acupuncture, in which the pain block from the message that the needle or burning cone of herbs gives to the point of stimulus, was only found centuries later by the West through science and technology.


Raymond Cheng, PhD DPA Thank you for visiting this TCM and acupuncture information website. If you have previously been to this website, you might have noticed that some of the pages on ancient historical ideas and holistic thinkings related to Chinese metaphysics are temporarily taken offline. This is because I will be revamping the whole website and be moving those information into a new \"Ancient Chinese Culture\" section so as to reflect a more current perspective on the interpretation of some of the fundamental concepts as well as to include some of the latest information in the area. But if you have just found this website for the very first time, I welcome you again and wish you could find what you require and, hopefully, you could also be benefitted from reading the articles I published on this website.

Please be patient and do come and check out this website frequently as it's being revamped.

Raymond Cheng, PhD DPA FRSA FRSPH

March 28, 2020.


This website is published, edited and designed by Raymond Cheng, and reflects only and only his personal views and opinions in his individual capacity. The information available at this website is not intended directly or by implication to either diagnose or treat any medical, emotional, or psychological condition or disorder. It is also not intended to create a physician-patient relationship between you and I or between you and Wyith Institute™ and The Office of Dr Raymond K K Cheng. The information here is not a substitute for advice and treatment provided by your physician or by another healthcare professional. It is always recommended that consultation with local healthcare providers be obtained for any of your specific health or medical concerns. Furthermore, any products that can be purchased (yet you can see I don't have much to sell here) through advertisers' banners or through links to other websites are not either explicitly or implicitly given any warranty or endorsement by me, my colleagues, Wyith Institute™ or any of its associated businesses.