Comparison of Terminologies and Concepts of Traditional Chinese Medicine (TCM) and Western Medicine

 

Dr. So Tsz Him,
Honorary Clinical Assistant Professor, Department of Clinical Oncology, The University of Hong Kong
Registered Chinese Medicine Practitioner
Member of the Education Group, Hong Kong Anti-Cancer Society

 

Host: Ms Wong Wing Chen Janet

 

 

Introduction

Hong Kong is a Chinese community. When we fall ill, while receiving Western medicine treatment, many of us also consult TCM practitioners to improve the situation. However, do we clearly understand what TCM theories entail? Or further, how are these theories viewed from the perspective of Western medicine? In this article, Dr. So Tsz Him will explain to us in detail.
 

Part 1 – Qi and Blood（氣、血）
Part 2 – Yin and Yang（陰陽）
Part 3 – Five Elements（五行）
Part 4 – The Five Zang-Organs（五臟）and Six Fu-Organs（六腑）
Part 5 – Meridians and Collaterals（經絡）
Part 6 – Constitution（體質）
Part 7 – Health Preservation（養生）

 

Part 1 – Qi and Blood（氣、血）

Wong: Hong Kong is a Chinese community. When we fall ill, while receiving Western medicine treatment, many of us also consult TCM practitioners to improve the situation. However, do we clearly understand what TCM theories entail? Or further, how are these theories viewed from the perspective of Western medicine? In this article, Dr. So Tsz Him will explain to us in detail.

Dr. So is both an oncologist and a TCM practitioner.

Dr. So, thank you very much.

So: You’re welcome.

Wong: First, let’s talk about "Qi"（氣）.

So: "Qi" represents the manifestation of the energy of organs.

TCM refers to "Qi" (氣) , and also mentions conditions like "lack of Qi" （沒氣）and "smooth Qi"（順氣） . How does TCM explain "Qi"? And how does Western medicine view "Qi"?

In fact, we often hear people say things like "Is it Qi and blood deficiency?"（氣血虛弱）, "Is it Qi deficiency（氣虛）?" or "Is it blood deficiency?（血虛）" We often mention "Qi and blood" together, but in TCM, "Qi"（氣）and "blood"（血）are two different yet related concepts.

Regarding "Qi", TCM considers it similar to a form of energy in the body. In fact, "Qi" exists in every part of the body. For example, judging whether a person’s breathing is good means checking if their "Lung Qi" （肺氣）is sufficient. A person with sufficient "Lung Qi" has a stronger function and more energy in the lung system—they may walk without getting out of breath and even climb uphill in one go. On the other hand, a person with insufficient "Lung Qi" will obviously have difficulty in breathing, easily become short of breath, and may get winded even after climbing two flights of stairs.

Let us also use "Spleen" （脾）as an example.

We often talk about "Spleen Qi deficiency"（脾氣虛弱）. The "Spleen"（脾）in TCM mainly refers to the digestive system. So "Spleen Qi deficiency" means the digestive system has relatively weak energy. Patients with this condition may feel full after eating just a little, because their digestive function is inherently poor; they may also easily have diarrhea, as their bodies cannot absorb many substances, which then leads to diarrhea.

From a TCM perspective, there are various types of "Qi", but overall, "Qi" refers to the energy of the body and the manifestation of the strength of some bodily functions. If a function is adequate, it is called "abundant Qi" （氣盛）or "strong Qi"（氣強）; if a function is insufficient, it is called "deficient Qi"（'氣虛）.

Wong: TCM attaches great importance to the so-called "Doctrine of the Mean"（中庸之道）. For something like "Qi", is the more the better?

So: Not necessarily. Sometimes "Qi" can be too strong. The most common case of "excessive Qi"（氣強）is the so-called "Liver Qi"（肝氣）—"excessive Liver Qi" is quite common among patients. In TCM, "Liver Qi" governs a person’s emotions. For example, a person’s nervousness or the drive to get something done is what we call "Liver Qi". Some people may have "excessively strong Liver Qi", making them prone to anger which is not good. In fact, very often, "excessive Liver Qi" is also harmful to the body and is an abnormal state.

Western Medicine’s Perspective on "Qi"

Wong: From the perspective of Western medicine, is there an equivalent concept to "Qi"? Is it "energy"?

So: Western medicine rarely mentions the concept of "energy". The reason is that modern Western medicine is mainly based on biomedicine—it focuses heavily on biology and biomedicine, emphasizing cells, blood vessels, and things that can be seen with the naked eye. In contrast, TCM is somewhat more inclined towards physics, focusing on energy changes (such as electric currents or magnetic fields). These things cannot be seen with the naked eye, but we know they exist.

Therefore, TCM views the human body more from the perspective of physics—focusing on things that may not be easily visible to the naked eye.

From the Western medicine perspective, "Qi" seems quite abstract, and it is unclear whether it truly exists. Therefore, mainstream Western medicine does not focus on "energy". However, some specialized fields or basic medical research do pay more attention to this aspect. For example, some studies have found that if a person has "Spleen and Stomach Qi deficiency"（脾胃氣虛）, when detected using infrared technology (such as measuring temperature), it turns out that the body parts corresponding to the spleen and stomach actually have a slightly lower temperature—this allows us to observe the difference in this "energy". Of course, if you press these areas with your hand, the temperature difference may be very small (not 5 to 10 degrees Celsius), but with sophisticated instruments, we can indeed see that there are changes in the body’s energy.

When a person gets angry, the so-called "Liver Qi" rises. Imaging results show that the temperature of the person’s head suddenly increases significantly. Our own feelings actually correlate with the temperature changes observed through such infrared technology.

However, from the perspective of mainstream Western medicine, there is no particular focus on "Qi" or "energy".

Part 2 – Yin and Yang（陰陽）

Wong: What is "Yin and Yang"?

So: If we only understand Western science and medicine, it is difficult to comprehend why TCM often refers to "Yin"（陰 ）and "Yang"（陽）, as well as "Wood, Fire, Earth, Metal, Water"（木、火、土、金、水）—these concepts seem quite abstract.

To understand them, we need to trace their origins. In China, there were the so-called "Yin-Yang School"（陰陽學說）and Taoist（道家）philosophy. When TCM took shape, it adopted the concepts of "Yin-Yang and Five Elements"（陰陽五行）.

So what exactly are "Yin and Yang"?

Emphasis on "Balance"

TCM places great importance on "balance". Let’s start with "Yin and Yang": essentially, everything is believed to have both "Yin" and "Yang" aspects.

"Yang" represents things that are relatively active, relatively warm, or a state where a bodily function is overly excited. Conversely, "Yin" refers to a state where the temperature is relatively low or a function is relatively weak.

In other words, TCM historically borrowed Taoist philosophy—the sky has day and night, and the human body is viewed in the same way. Day and night must be balanced; for example, a day with only daylight is impossible, and a day with only night is also impossible. Similarly, the human body cannot have only "Yang" or only "Yin" all the time.

Example: The "Liver"

Let’s take an example. We often hear the term "Liver Yang Hyperactivity"（肝陽上亢）. Here, "Liver"（肝）—if translated literally—refers to the "liver" in Western medicine.

However, in TCM, "Liver" does not only refer to the liver organ itself; it broadly encompasses a person’s willpower, emotions, and motivation to get things done.

"Liver Yang Hyperactivity" means a person is in a state of prolonged excitement, overactivity, or overwork. Sustaining this state for a long time is abnormal. Such people often struggle to control their emotions—they may easily lose their temper or feel fatigued. These are the manifestations of so-called "Liver Yang Hyperactivity".

In the case of "Hyperactive Yang"（陽亢）"Yin" （陰）becomes relatively deficient. This condition is called "excessive Yang and deficient Yin"（陽盛而陰衰）, which is harmful to health.

Another Example: The "Heart"

Let’s take another organ as an example—"Heart Yin Deficiency"（心陰不足）which is also common. Clinically, in terms of heart rate, people with "Heart Yin Deficiency" often feel their heart beating rapidly for no apparent reason, or experience unexplained anxiety. This occurs because "Heart Yin" （心陰）is relatively insufficient, making the "Heart Yang"（心陽） (functional activity of the heart) hyperactive, i.e., the heart function is overly intense.

So, after all this talk about "Yin and Yang", it essentially boils down to a state of balance.

Analysis from the Western Medicine Perspective

Wong: From the Western medicine perspective, is there any equivalent meaning to "Yin and Yang"?

So: From the Western medicine viewpoint, there is no direct concept of "Yin and Yang". However, some of our understandings of bodily organs and their functions bear similarities to the concept of "Yin and Yang".

For example, we have a nervous system called the "autonomic nervous system", which is not under voluntary control. For instance, we cannot control our heart rate —this is because the body has an autonomic nervous system that regulates it: when needed (e.g., during running), the heart rate naturally increases; when we are about to sleep, the heart rate naturally slows down.

Sympathetic Nervous System

The autonomic nervous system consists of two major components: the "sympathetic nervous system" and the "parasympathetic nervous system". These two systems are somewhat analogous to "Yin and Yang".

The sympathetic nervous system is like the "Yang Qi" of the body. When stimulated—for example, when a person is about to run, handle many tasks (not during leisure time, such as work), or feels nervous—the sympathetic nervous system is activated. This leads to a faster heart rate, sweating, or muscles tensing up in preparation for action.

In TCM terms, this activation of the sympathetic nervous system is a state of "abundant Yang Qi"（陽氣過盛）.

Parasympathetic Nervous System

In contrast, the parasympathetic nervous system promotes relaxation and rest. For example, the sense of contentment we feel after eating is when the parasympathetic nervous system is functioning. Similarly, when we sleep, our heart rate slows down relatively—this is when the parasympathetic nervous system dominates.

Therefore, in Western medicine, the sympathetic and parasympathetic nervous systems must be balanced. Sometimes one may be more active, and sometimes the other more—depending on the body’s actual needs.

Dysregulation of the Sympathetic and Parasympathetic Nervous Systems

Sometimes the sympathetic nervous system may overreact, becoming completely out of control and exceeding normal limits. For example, some people with panic disorder experience sudden, unexplained activation of the sympathetic nervous system—even when there is no real threat (e.g., not being chased by a lion or tiger). They may feel sudden panic even when safe at home, with symptoms like cold sweats and a rapid heartbeat. This is a state of excessive sympathetic nervous system activity.

As you can tell from my explanation just now, this is somewhat similar to the TCM concept of "Liver Yang Hyperactivity"—a person cannot control themselves, often gets angry or irritable, and may even experience headaches or other discomforts.

This does not mean that the sympathetic and parasympathetic nervous systems in Western medicine are exactly equivalent to "Yin and Yang" in TCM. However, we can see similarities: the sympathetic nervous system is associated with the "fight-or-flight" response—you stay alert to potential threats and prepare to respond. The parasympathetic nervous system, on the other hand, is linked to "nurture and nourish"—similar to the TCM concept of "nourishing" the body. These two systems must be balanced for a person to be in a comfortable state.

The so-called "Yin-Yang balance" does not mean the two must be at the same level. Instead, sometimes we need the "fight-or-flight" response, and sometimes we need "nurture and nourish"—depending on the situation. Neither should however exceed an upper limit nor fall below a lower limit.

Part 3 – Five Elements（五行）

Wong: Now I will like to ask about the "Five Elements" (五行). People in Hong Kong often talk about "Metal, Wood, Water, Fire, Earth" （金木水火土）— what exactly do these refer to? And is their order fixed?

So: The "Five Elements" is a rather complex philosophy.

In simple terms, it is derived from the concept of "Yin and Yang"（陰陽）.

Although we usually mention the "Five Elements" in the sequence of "Metal, Wood, Water, Fire, Earth" in daily life, in both Traditional Chinese Medicine (TCM) and other branches of traditional Chinese knowledge, the order "Wood, Fire, Earth, Metal, Water" is commonly adopted（木火土金水）.

Some may say we don’t need to be rigid about the order, but in fact, it carries special meaning—why is the order necessarily "Wood, Fire, Earth, Metal, Water"?

Because the ancient scholars who developed the "Five Elements" theory based it on observing the changes of the sun’s position relative to the earth throughout a day.

Wood（木）: Corresponds to sunrise, usually around 5, 6, or 7 in the morning. When the sun rises, sunlight begins to increase. This early morning period is associated with "Wood", which is why "Wood" is listed as the first of the Five Elements in TCM.

Fire（火）: Refers to midday, roughly from 11 a.m. to 1 p.m.—the time when "Yang Qi" is at its strongest. This period is linked to "Fire".

Metal（金）: Occurs when "Yang Qi" (陽氣）starts to decline, around 5 or 6 p.m. as dusk falls and the air begins to feel cooler. This time is associated with "Metal".

Water（水）: Corresponds to midnight, approximately from 11 p.m. to 1 a.m.—the deepest part of the night. This period is linked to "Water".

We still have "Earth"（土） left. In fact, "Earth" represents the middle of this cycle—it lies at the center of the Five Elements.

Originally, this concept was applied in fields like philosophy, astronomy, and even traditional feng shui （風水）. TCM, which drew on certain Taoist （道家） philosophical ideas (sharing the same origin), adopted the order of "Wood, Fire, Earth, Metal, Water", which was determined based on the daily cycle of day and night.

To put it more simply: we can map the daily rhythm to the Five Elements. Later, it was also believed that this correspondence applies to the annual cycle:

Spring（春） corresponds to "Wood（木）”—-as trees start to grow in spring.

Summer（夏）, being hot, corresponds to "Fire（火 ）".

Autumn（秋）, when the weather begins to cool, corresponds to "Metal（金）”.

Winter（冬）, when it turns cold, corresponds to "Wate（水）”.

All the transitional changes in between are associated with "Earth"（土）.

Wong: Does the Five Elements theory include the concepts of "mutual generation" （相生）and "mutual restriction" （相剋）?

So: Those are the original core ideas of the "Yin-Yang and Five Elements" theory. After further development over time, they evolved into the "mutual generation and mutual restriction of the Five Elements"（相生相剋） that we often hear about today—meaning one element generates another and one restricts another. But let’s not digress too far; let’s focus back on the medical aspect.

Part Four —- The Five Zang-Organs（五臟）and Six Fu-Organs（六腑）

The Five Zang-Organs

Wong: How does this apply to the human body?

So: When the theoretical system of Traditional Chinese Medicine (TCM) began to take shape more than 2,000 years ago, this concept was actually borrowed to categorize the human body into the so-called "Wood, Fire, Earth, Metal, Water" elements, which correspond to the five "Zang-organs" – the Liver, Heart, Spleen, Lung, and Kidney：

• Wood——Liver （木對肝）
• Fire ——Heart（火對心）
• Earth——Spleen（土對脾）
• Metal——Lung（金對肺）
• Water——Kidney（水對腎）

However, these five "Zang-organs" do not simply refer to individual organs, but rather five systems of the human body.

Take "Water" as an example. We know that the "Kidney" in TCM belongs to the "Water" element. But in terms of "Water", it does not only refer to the "kidney" (as defined in Western medicine); it includes the organ or system known as the "Kidney" in TCM, covering the kidney (kidney in Western medicine), adrenal gland, reproductive system, and some muscles of the lower back. All functions of this system or these parts fall under the "Water" element.

To put it more practically, when TCM defined these five systems, it borrowed philosophical concepts like "Wood, Fire, Earth, Metal, Water" (prevalent at that time) for classification.

Wong: TCM does not rely on anatomy, so how did it understand the structure of the human body?

So: TCM has a long history. More than 2,000 years ago, the ancient Chinese did not practise anatomy in the way we do today. Therefore, their understanding of these systems back then was mainly based on observation. But was it entirely based on observation?

I mentioned earlier that TCM borrowed philosophical concepts and applied them. In fact the development of TCM also incorporated some anatomical principles. The earliest surviving TCM classic is likely Huangdi Neijing (Inner Canon of the Yellow Emperor)（黃帝內經）, written over 2,000 years ago. Not long after Huangdi Neijing, there was another classic called Nanjing (Classic of Difficult Issues（難經）, where "Nan"（難） means "difficult"). Nanjing actually contains some anatomical knowledge on each organ, such as the length and weight of the organ. Thus, the development of TCM was not completely without anatomy, nor did it rely entirely on it.

A. TCM Spleen-Stomach（脾）vs. Western Medicine Stomach and Digestive System

Wong: Let’s now discuss the "Five Zang-organs" in detail.

First, how should we understand the "Spleen-Stomach" in TCM and the "stomach and digestive system" in Western medicine?

So: We often hear people say "This person has a weak Spleen-Stomach"（脾胃弱）– this is a common expression in TCM, and even ordinary people use it. But from a Western medicine perspective, this is confusing: the "Spleen" （脾）in Western medicine is the "spleen" (an immune organ), so why is it grouped together with the "stomach"（胃）? Their functions seem completely unrelated.

However, those who have studied anatomy know that the spleen (located roughly on the left side of the body) is an immune organ, but one end of it is closely attached to another organ – the pancreas. The pancreas is a vital digestive organ. Anatomically, the spleen and pancreas are very close to each other; and they often stick together when removed during dissection. I assume that in ancient times, when people dissected and removed organs, they did not just take out the spleen (the immune organ) alone, but regarded the two adhering organs (the spleen and pancreas) as a single unit. Therefore, with the anatomical techniques available at that time, they were seen as one organ.

In fact, anatomically, the tail of the pancreas is indeed very close to the spleen. Hence, these two organs were collectively called the "Spleen" in TCM. Moreover, since the pancreas is also very close to the stomach, the three (spleen, pancreas, and stomach) were linked together, forming what is known as the "Spleen-Stomach" （脾胃）in TCM.

TCM holds that the Spleen-Stomach not only governs digestion but also is related to immunity. Many people with a strong Spleen-Stomach tend to have better immunity and are less likely to get sick.

Therefore, TCM is not absolutely without anatomical concepts. It is just that more than 1,000 to 2,000 years ago, the level of anatomical knowledge, techniques, equipment, and understanding at that time was different from the Western anatomical system we have today, which is supported by a wide range of advanced instruments.

B. TCM Heart（心）vs. Western Medicine Heart and Circulatory System

Wong: There is another thing I find confusing: we consider the brain the most important organ, but it does not appear in the Five Zang-organs. Why is that?

So: In TCM, part of the brain’s functions fall under the functions of the "Heart"（心）, and another part under the functions of the "Kidney"（腎）. It may not be clear how to specifically distinguish them, but we can infer clues from existing literature. For example, some people who are in a low mood or have insufficient "Heart Blood"（心血） may suffer from chronic sleep deprivation due to studying or work.

What happens to people with insufficient Heart Blood? In addition to having a paler complexion, they may sometimes have poor concentration or feel unhappy. You might ask: insufficient Heart Blood clearly refers to the Heart (as a physical organ), so why would it affect the functions of the brain? This brings us back to how TCM defined its systems: it was based on observing the functional manifestations of the human body. For instance, people with "Hyperactivity of Heart Fire" (a TCM term meaning the relative excess of Yang Qi in the Heart)（心火盛） may have a faster heartbeat and experience unexplained palpitations.

When we feel scared, our heartbeat speeds up. Therefore, TCM believes these two phenomena are closely related and classifies emotional activities under the "Heart" system. It holds that when a person experiences any emotion, the first physical response of the body often comes from the Heart. For example, when feeling unhappy, one may have a sensation of "suddenly being weighed down" in the chest (related to the Heart). There is also a rare condition in Western medicine called "broken heart syndrome", which was first discovered in Japan. It occurs when people are exposed to intense emotional stress – such as the death of a family member, extreme overwork, or a shocking event – leading to actual heart failure.

Western medicine and TCM cannot be completely compared, but by synthesizing all such phenomena, we can see that TCM’s claim that some emotional activities are governed by the Heart is not without reason.

So: In fact, our circulatory system is also closely related to emotions. To give a simple example, when we are very nervous, our circulatory system changes immediately: our hands and feet feel cold because our blood vessels constrict. Or when we are very happy and laugh heartily, our blood pressure may rise because our blood vessels dilate.

TCM observed that emotional changes first manifest in the Heart and blood vessels (through congestion or lack of congestion). Therefore, it linked these two (emotions and the Heart) together. Today, when we study TCM from a modern perspective, we can also understand the TCM theory that "the Heart stores the Mind（心藏神志）.

C. TCM Liver（肝） vs. Western Medicine Liver

Wong: What about the "Liver" then?

So: The liver (in Western medicine) is connected to the bladder, but does it exactly belong to the digestive system?

In Western medicine, one of the liver’s functions is to aid digestion (e.g., bile secretion); however, the liver also has a crucial detoxification function. The liver contains many blood vessels. In TCM, there is a theory that "the Liver stores Blood", meaning the liver contains a large amount of blood – this aligns somewhat with Western medicine.

But in TCM, the Liver does not only refer to the liver organ (as in Western medicine). TCM states that "the outward manifestation of the Liver is on the nails" – in other words, to assess the health of a person’s Liver in TCM, we can look at their nails and tendons. People who are often tense or irritable usually have tight tendons, which is what TCM calls "excessive Liver Qi". Why does this happen? Because "Liver Blood" is insufficient to nourish the tendons, causing Liver Qi to become stagnant and tense, and the person tends to feel tense overall. This is why we often see tense people with tight shoulders, and in some cases, joint inflexibility due to long-term tension.

D. TCM Lung（肺） vs. Western Medicine Lung and Respiratory System

Wong: Is the Lung in TCM equivalent to the respiratory system in Western medicine?

So: The understanding of the Lung in TCM and Western medicine is relatively consistent, mainly focusing on whether the respiratory Qi is sufficient.

On the other hand, TCM believes that the Lung is closely related to the skin.

This may be difficult to understand from the perspective of modern medical knowledge – why would the Lung be related to the skin? However, we can gain some insight from diseases. The upper part of the lung is connected to the respiratory tract and nose, which are actually closely related to the skin. Healthy people may not notice this, but those with allergies know that asthma (a Lung-related allergy), allergic rhinitis (commonly known as nasal sensitivity), and eczema (a skin allergy) are often linked.

Very often, these three conditions occur simultaneously in a child (though they can appear at any age). When allergies occur, skin allergies, lung allergies (asthma), and nasal allergies (rhinitis) usually present together. Therefore, in TCM, when treating eczema or asthma, practitioners often check whether the patient also has allergic skin rashes.

E. TCM Kidney（腎） vs. Western Medicine Kidney and Excretory System

Wong: What about the Kidney then?

So: The Kidney in TCM is relatively difficult to understand, but it becomes less confusing once you grasp the key points.

The Kidney in TCM includes the kidney (as in Western medicine), ureter, and bladder – i.e., the entire urinary system. In addition, the Kidney in TCM also governs reproduction: for example, male reproductive organs (such as testes) and female reproductive organs (such as ovaries or uterus) are all governed by the Kidney system in TCM.

At first glance, these functions (urination and reproduction) seem unrelated. But if we look at it from the perspective of modern medicine – specifically embryology (the study of how an embryo develops from a single cell into a fetus in the mother’s womb) – we can gain a better understanding.

It turns out that during embryonic development, the kidneys (the organs) are closely attached to the female ovaries or male testes. As the latter develop, they move downward toward the abdomen while adhering to the kidneys.

When they reach a certain position, the kidneys stop in the abdomen. For females, the ovaries also remain in the abdomen; for males, the testes continue to move downward into the scrotum.

Thus, from a cellular perspective, the kidneys and reproductive organs share the same origin. We can also understand this through diseases: for example, there is a common concern among Chinese men about "Kidney Deficiency" (a TCM term)（腎虧）. What are the signs of Kidney Deficiency? They may include poor erectile function, infertility, and concurrent symptoms like difficult urination or urinary incontinence.

From a Western medicine perspective, some diseases affect both the urinary and reproductive systems – such as benign prostatic hyperplasia or prostate cancer. This is consistent with TCM’s view that the Kidney system governs both reproductive and urinary functions.

Six Fu-organs（六腑）

Wong: Then what about the "Six Fu-organs"?

So: If we don’t include the "Triple Energizer" (Sanjiao) （三焦）in the count, there are actually only Five Fu-organs.

These Five Fu-organs correspond to the Five Zang-organs (Five Viscera). In Traditional Chinese Medicine (TCM), the so-called "Five Zang-organs and Six Fu-organs"（五臟六腑） or "Five Zang-organs and Five Fu-organs" follow a one-to-one correspondence:

The Liver（肝）corresponds to the Gallbladder（膽）;

The Spleen（脾）corresponds to the Stomach（胃）;

The Heart（心）corresponds to the Small Intestine（小腸）;

The Lungs（肺）correspond to the Large Intestine（大腸）; and

The Kidneys（腎）correspond to the Bladder（膀胱）.

Wong: So that’s how it works!

So: Traditionally, TCM holds that Fu-organs are usually hollow. For example, the Heart—though it contains blood—is relatively solid; whereas the Small and Large Intestines are relatively hollow, as they are organs that hold food, aid digestion, and store waste.

The Stomach is also primarily hollow; the Gallbladder stores bile.

The Bladder is also hollow.

Therefore, one way to distinguish between the Five Zang-organs and Six Fu-organs is to say that the Fu-organs are subordinate to the Zang-organs.

From a Western medicine perspective, both the Zang-organs and Fu-organs are simply called "organs"—each has its own distinct function, and there is no hierarchy of "importance" or "lower rank." But such a hierarchy exists in TCM.

Wong: But it does sound like the Fu-organs are considered a lower rank.

So: It may seem that the Fu-organs are at a lower level, but they are actually very important. To put it simply, among the Five Zang-organs and Six Fu-organs, the Zang-organs are like "full members," while the Fu-organs are "associate members."

Part Five – Meridians and Collaterals（經絡）

Definition

Wong: We often hear that acupuncture is related to meridians and collaterals（經絡）. What exactly are "meridians and collaterals"（經和絡）

So: Whether it’s acupuncture（針灸）, tuina(therapeutic massage)（推拿）or acupoint massage（穴道按摩）, they are often closely related to meridians（經）and collaterals（絡）.

In TCM, it is believed that there are channels in the human body—on the surface of the hands, feet, and other areas—that connect the Zang-organs and Fu-organs, enabling communication and balance between them.

These are the meridians and collaterals, which can be divided into two categories:

Meridians (Jing)（經）: Twelve major meridians, the main trunks—like the highways we talk about today, the twelve largest "corridors" in the body;

Collaterals (Luo)（絡）: The smaller branches of the meridians, like minor roads.

Analysis from a Western Medicine Perspective

Wong: How is this understood from a Western medicine viewpoint?

So: Let’s explore whether we can use modern medicine to understand what meridians and collaterals actually are.

Since the "acupuncture boom" spread to the United States in the 1970s, there have been numerous studies on meridians and collaterals over the past decades. Researchers tried to figure out what the ancient Chinese based this system on, and initially wondered if meridians might be similar to blood vessels. Later, however, they found this was not the case—from an anatomical perspective, there is no direct match between the physical pathways of meridians and those of blood vessels or nerves.

In the past five to six years, some studies have started to yield clues.

We know the human body has muscles, covered by fat, which is in turn covered by skin. It turns out there is another layer between the fat and muscle: a layer of connective tissue called fascia, which covers the muscles. We often see this membrane when eating meat— it is most noticeable on pork. Humans also have this membrane covering their muscles; in English, it’s called "fascia."

People have long known about fascia and thought its only role was to hold muscles in place, allowing them to contract and expand. But recent findings show that fascia has a slight electrical conductivity. In fact, the nerves rely on tiny electrical currents from the fascia to control the movement of the hands and feet. This means there is another type of tissue in the body (other than nerves) that can conduct electricity.

Moreover, researchers have found that many acupoints targeted in acupuncture—such as Zusanli (a common acupoint on the leg)（足三里） or Jianjing (an acupoint on the shoulder) （肩井）—are locations where fascia is particularly concentrated and thick. Acupuncture also requires precise depth; the needle must reach a specific depth to produce the "deqi" (needle sensation) （得氣） that brings therapeutic effects.

It has been observed that acupuncture needles only work when they reach the fascia layer above the muscles. A needle that is too shallow has little effect; it must penetrate to a certain depth to reach this layer, which is when the typical acupuncture sensations—soreness, numbness, distension, and pain—occur.

Therefore, from a modern scientific perspective, it is possible that the "meridians and collaterals" described in TCM refer to this fascia layer. Since the body is covered with muscles, this fascia essentially wraps around the entire body—from the hands to the head, back, and down to the toes. This suggests that the overall conductive function of meridians and collaterals likely depends on the function of this fascia layer.

Over a decade or two ago, studies in Taiwan already found that when testing certain acupoints, some had particularly strong electrical conductivity or unusually low electrical resistance. When these locations were compared to the meridian pathways commonly depicted in TCM, correspondences were found.

However, even today, we still cannot fully understand meridians and collaterals: why they follow their specific pathways, or why ancient Chinese physicians mapped them that way. At the very least, though, we know that tools—such as electrical devices and detection methods—may help verify in the future whether the pathways of the Twelve Main Meridians truly match the descriptions from ancient records. If adjustments to these traditional maps are needed later, it would not be surprising.

Part 6 – Body Constitution（體質）

Western Medicine Perspective

Wong: In traditional Chinese medicine humans are categorized into different body constitutions（體質）, and often mention nine types, such as balanced constitution（平和）, yang-deficient constitution（陽虛）, yin-deficient constitution（陰虛）, etc. It is also believed that a person may be born with a certain constitution. So, does Western medicine have such a "constitution classification"?

So: In fact ancient Greek medicine had similar classifications, categorizing people based on different physical forms. However, in the modern biomedical or Western medicine system, it is rare to directly say "you belong to a certain constitution".

Nevertheless, we do have similar explorations. For example, in recent years, many people have undergone DNA testing, and there are numerous related advertisements on the market. Through DNA testing, one may find out which diseases they are prone to develop in the future, which substances their body are particularly sensitive to, and even find some basis for estimating personality, intelligence, and future development tendencies.

But DNA is only one of the influencing factors; there are many other factors such as environment and living habits that together shape an individual’s physical condition.

Therefore, although Western medicine does not have the concept of constitutions like "yang deficiency" or "yin deficiency", it also tries to identify each person’s disease tendencies through genetic research. For instance, some people are more prone to heart disease, while others are more likely to have liver problems. Essentially, this is an exploration of individual differences.

Traditional Chinese Medicine (TCM) Classification

Wong: Then, what does TCM rely on for classification?

So: TCM has discovered through long-term clinical observations that different people do have differences in their tendency to get sick.

For example, a long time ago, Huangdi Neijing (Inner Canon of the Yellow Emperor) （黃帝內經）recorded that wealthy people in ancient times were prone to developing sores on their feet. The so-called "excessive consumption of rich and greasy food leading to large boils on the feet" （高粱厚味，足生大疔）means that those who often eat greasy and refined food are prone to sores on their feet. It might have sounded strange at that time, but it can be clearly explained using modern medical concepts: most people in ancient times were poor farmers who had heavy labor and a simple diet; only the wealthy ate well and exercised little. In fact, this was the early symptom of diabetes, and the sores on the feet were exactly the complications related to diabetes. It can be seen that TCM has long observed the law that "certain people are more likely to suffer from specific diseases" from lifestyle patterns.

Another example is the "yin-deficient constitution"（陰虛）mentioned in TCM, which is relatively common in Hong Kong. Some people are born with it, while others develop it. People with yin-deficient constitution usually sleep less, have dry skin, are relatively thin, are not afraid of cold but sensitive to heat, and feel uncomfortable when the weather gets hot. Such people are also more likely to suffer from lung diseases. Previous TCM classics mentioned that people with yin-deficient constitution are particularly prone to tuberculosis; conversely, people with severe tuberculosis will also become very thin and cannot gain weight no matter how much they eat. This completely corresponds to TCM observations. The only difference is that Western medicine believes "tuberculosis causes weight loss", while TCM holds that "it is the prior existence of yin-deficient constitution that makes one prone to tuberculosis" – the two have different logical entry points.

There is also a common "dampness-excessive constitution"（濕重體質）. People with this constitution often feel tired, are relatively fat with more body fat, dislike exercise, and sometimes experience gastrointestinal discomfort, diarrhea and other symptoms. In modern society, there are also many people with this constitution, mostly due to frequent consumption of raw, cold and greasy food and lack of exercise.

Wong: Can we change our own constitution?

So: Constitution is not fixed; it can be changed with adjustments to lifestyle. For example, if you used to stay up late often, you might have gradually developed a yin-deficient constitution. But if you adjust your work and rest schedule and develop regular living habits over the next five or ten years, your constitution will gradually improve.

Preventive Treatment of Diseases（治未病）

When it comes to constitution regulation, we have to mention the concept of "preventive treatment of diseases" that has become very popular in TCM in recent years. "Preventive treatment of diseases" （治未病）actually includes two meanings: the first is "preventing diseases before they occur"（未病先防）, and the second is "preventing deterioration once a disease occurs"（既病防變）.

The so-called "preventing diseases before they occur" is similar to what Western medicine calls "preventing diseases before they happen". For example, even if you don’t have diabetes, you should still try to control your diet, eat less greasy food and exercise more; strictly speaking, getting vaccinated now also falls into the category of "preventive treatment of diseases" – all are measures to protect against diseases before they occur.

As for "preventing deterioration once a disease occurs", it refers to timely treatment when a disease first appears to prevent the condition from worsening or causing other complications. For example, frequent coughing may seem like a minor issue, but prolonged coughing will consume yin energy, damage lung qi, gradually lead to weight loss, and even develop into more serious lung diseases. Therefore, in the early stage of coughing, whether it is a common cough or an allergic cough, it should be cured as soon as possible to avoid letting a minor illness turn into a serious one. This is the core of "preventing deterioration once a disease occurs".

Sub-Health（亞健康）

In the past, the concept of Western medicine mostly centered on "treating diseases", holding that "for a person to have no diseases means that he is healthy"; while "health preservation"（養生） is a part that TCM focuses more on ——even if one is not sick, TCM aims to improve the body’s condition through regulation. Western medicine might have questioned this in the past: "What does 'better' mean? Isn’t being disease-free enough?" But TCM does not see it this way: even if there is no clear disease, if the body’s functions do not reach the optimal state, it cannot be regarded as true health. This is actually very similar to the commonly mentioned "sub-health state"（亞健康 ） nowadays – it is neither a disease nor complete health, but a state in between: there are no substantial symptoms, but the body’s functions cannot be fully exerted.

Part 7 – Health Preservation（養生）

Wong: We Chinese often talk about "health preservation" (Yang Sheng)（養生）. Can you explain it?

Exercise

So: Chinese people have always attached great importance to health preservation. On one hand, it is to pursue longevity; on the other hand, even without illness or pain, people want to make their bodies stronger through health preservation. For example, practicing Tai Chi（太極）, Qigong（氣功）, or doing other exercises can not only enhance muscle strength but also improve the function of the respiratory system. Modern research has also confirmed the effects of health preservation: regular Tai Chi practice, for instance, can help prevent osteoporosis, reduce the risk of falls in the elderly, and improve respiratory function, which indeed contributes to longevity.。

Diet Therapy

Of course, health preservation is not just about practicing martial arts or qigong; it also includes diet therapy. For example, when the weather is dry, people boil nourishing soups; when the weather is humid and there is internal heat in the body, they cook "Qing Bu Liang" (a traditional Cantonese herbal soup) （清補涼）to clear away dampness and heat. These are health preservation methods familiar to people in Hong Kong, aiming to keep the body in a balanced state and reduce the chance of getting sick.

In fact, health preservation is closely connected to the concept of "preventive treatment of diseases". Although modern Western medicine has not formally put forward the concepts of "health preservation" or "preventive treatment of diseases", similar ideas have emerged in some Western societies. For example, in the past decade or two, many people have started going to the gym, and exercise has become a trend. People are no longer satisfied with "being disease-free"; instead, they hope to have better physical functions, walk faster, have stronger balance, and even have a better figure. This is essentially what Western society refers to as "health preservation".

In terms of diet, some people try "intermittent fasting" or the so-called "Western detox diet". The purpose of these methods is similar to that of TCM health preservation—both aim to regulate the body's condition—only the specific approaches differ.

As for the origin of the term "sub-health", it was put forward by the World Health Organization (WHO) as early as thirty or forty years ago. In the past, when society was not affluent enough, people were more concerned about how to "treat existing diseases" and rarely paid attention to "sub-health". However, in many developed regions now, people's focus has shifted from "treating diseases" to "making the body stronger", and sub-health has gradually gained attention.

Wong: Thank you so much!

So: You are welcome.

(July 2024)