Always Catching Colds With a Thick White Tongue Coating? Song Dynasty Formula Master Doctor Xu Shuwei Treats Cold Damage With a White Slippery Tongue Coating (Zhi Zi Tang to Induce Vomiting, Then Xiao Chai Hu Tang to Harmonize)

Patient search words: always catching colds / frequent colds / thick white tongue coating / greasy white tongue coating / feeling hot and cold in turns / bitter taste in the mouth and dry throat / excessive dreaming / anxiety and tension

Corresponding medical terms: shao yang pattern (shao yang zheng) · externally contracted illness · constrained liver qi (gan qi bu shu) · stagnant qi movement (qi ji yu jie) · Minor Bupleurum Decoction pattern (xiao chai hu tang zheng)

The opening: with one glance at the tongue, the doctor understood the illness — but where did this skill come from?

Today we continue the stories of Doctor Xu Shuwei, the great formula master of the Song dynasty. Doctor Xu Shuwei was a celebrated physician of the transition between the Northern and Southern Song dynasties, known by his courtesy name Zhike and honored as “Scholar Xu” (Xu Xueshi). He was one of the founders of the classical formula school (jing fang pai). After Zhang Zhongjing’s books appeared, later generations used them very little; it was only in the Song dynasty that a group of physicians — Doctor Xu Shuwei, Doctor Zhu Gong (Zhu Hu), and others — promoted and applied them together, with outstanding results, until a whole school took shape: the classical formula school, which carried Zhang Zhongjing’s teachings forward and spread them widely. Doctor Xu Shuwei devoted himself to studying the cases treated with Zhang Zhongjing’s formulas. His book Discussion of Ninety Cases of Cold Damage (Shang Han Jiu Shi Lun) is among the earliest and most weighty case-record monographs in Chinese medical history.

So which case are we discussing today? The case of the white slippery tongue coating (she shang bai hua tai). This one is especially interesting — it is one of the earliest tongue-diagnosis records in the history of Chinese medicine. Think back: in all the cases we have discussed so far, have you ever seen a tongue diagnosis recorded? Almost never. Why? Because behind it lies a story of nearly a thousand years.

Who was the patient? Hot and cold in turns, a tight chest, and a white slippery coating on the tongue

The original text of Discussion of Ninety Cases of Cold Damage records: in the fifth month of the ding-wei year, a fellow villager of Doctor Xu, Xing Yuanhui, contracted cold damage (shang han).

What were his symptoms?

• Alternating chills and fever (han re wang lai): hot for a while, then the fever recedes and cold comes on — one moment shivering with cold, the next moment feverish;
• Oppression below the heart (xin xia yu men): “below the heart” refers to the chest area — a feeling of tight oppression and blockage right in the middle of the chest;
• White slippery tongue coating: a layer of white coating on the tongue, somewhat slippery — moist and water-slick to the look.

💬 Note from Doctor Luo: Friends, look back at all the cases we have discussed — did you ever see tongue diagnosis recorded? This is almost the first time! With the record of the white tongue coating, tongue diagnosis begins to appear. And this brings me to my own specialty — I study tongue diagnosis. You may wonder: why did tongue diagnosis appear only now? Which TCM doctor today doesn’t look at the tongue? But let me tell you, it was not always so — tongue diagnosis developed far later than pulse diagnosis.

The thousand-year history of tongue diagnosis (1): occasional mentions in the Nei Jing, clinical use by Zhang Zhongjing — but never a system

Let Doctor Luo trace the history of tongue diagnosis for everyone; this thread is especially precious:

The era of the Huang Di Nei Jing (Yellow Emperor’s Classic of Internal Medicine). The Nei Jing already mentions the tongue in many places, treating tongue signs as a diagnostic indicator — but without system: it is brought up only occasionally, not universally, and lacks structure.

Zhang Zhongjing’s Shang Han Za Bing Lun (Treatise on Cold Damage and Miscellaneous Diseases). With Zhang Zhongjing, tongue diagnosis truly entered clinical practice. When Zhang Zhongjing examined patients, the shape and condition of the tongue had already become one of his bases for judging disease — but he still used it sparingly, recording it only from time to time.

The Sui and Tang dynasties. Later generations accumulated experience over successive dynasties. In the Sui-Tang period, works like Doctor Sun Simiao’s Bei Ji Qian Jin Yao Fang (Essential Prescriptions Worth a Thousand Gold) contain a little tongue diagnosis, but not much.

💬 Note from Doctor Luo: Remember: Chinese tongue diagnosis developed step by step; it was not complete from the start. The ancients pointed out the direction, but limited by the conditions of their time, they never summarized it into a system — and that is precisely the work left for us: to keep enriching it.

The thousand-year history of tongue diagnosis (2): the first monograph in the Yuan dynasty, saved by Doctor Xue Lizhai’s printing in the Ming dynasty

It was not until the Yuan dynasty that a dedicated book appeared: Ao Shi Shang Han Jin Jing Lu (Ao’s Golden Mirror of Cold Damage Tongue Diagnosis) — the first monograph on tongue diagnosis in China.

The author’s surname was Ao — Master Ao (Ao Jiweng). Hearing the surname “Ao,” you might think he was Mongolian — he was not; he was Han Chinese. He combined tongue diagnosis with cold damage disease: at each stage of cold damage, what the tongue looked like — he summarized it item by item. This is why the rise of tongue diagnosis is intimately tied to externally contracted illnesses and cold damage — tongue diagnosis almost came into being to annotate and explain cold damage.

Yet after the book was written, it did not spread widely. The man who truly popularized it was Doctor Xue Lizhai (Xue Ji), the director of the Imperial Academy of Medicine in the Ming dynasty.

💬 Note from Doctor Luo: There is a story here. While Doctor Xue Lizhai served at the Imperial Academy in Beijing, he saw a practitioner who diagnosed with astonishing accuracy — extremely clear assessments. He asked privately: what book do you read? The man said: a book on tongue diagnosis. Doctor Xue Lizhai asked to borrow it, and the man refused — it was a family secret, not to be shared — he used it in private in his own household! You see, even the director of the Imperial Academy could not borrow it.

Later Doctor Xue Lizhai took up a post at the Imperial Academy in Nanjing — the Ming dynasty had two capitals: Beijing ran one set of government institutions, and Nanjing another. While browsing the library of the Nanjing academy, he came upon Ao’s Golden Mirror of Cold Damage Tongue Diagnosis, which explained everything clearly and even included colored tongue illustrations — obvious at a glance.

At that point Doctor Xue Lizhai did something of very high character: he did not copy the book and keep it for himself. His thought was — how can we raise the effectiveness of every physician in the realm? And so he had the book printed.

💬 Note from Doctor Luo: So the popularization of Ao’s Golden Mirror owes a great deal to Doctor Xue Lizhai. Spreading a work like this requires a person of influence to publicize it in one stroke, and then everyone learns of it. Doctor Xue Lizhai, kind and generous of heart, printed the book — and from that moment on, physicians everywhere knew: you can actually diagnose by looking at the tongue. The spread of tongue diagnosis rests entirely on that one stroke of his.

The thousand-year history of tongue diagnosis (3): the Qing dynasty Warm Disease school makes it “blanket the sky and cover the earth”

In the Qing dynasty, the Warm Disease doctrine (wen bing xue shuo) arose. The Warm Disease school argued: externally contracted illness is not all about cold — there is also warmth and heat. So how do you prove it is heat and not cold? They discovered — the tongue is different!

When struck by cold, the tongue is white; when there is heat, the tongue is red or purple. So the Warm Disease physicians placed enormous weight on tongue diagnosis; in their consultations tongue signs appear “blanket the sky and cover the earth” — the pulse may not always be clear, but cold versus heat shows on the tongue with immediate effect.

💬 Note from Doctor Luo: So in the Qing dynasty, tongue diagnosis suddenly flourished and matured rapidly, and many monographs on tongue diagnosis appeared. From that time on, physicians basically always looked at the tongue. Today, any TCM doctor records the tongue picture in detail. You see — without the contributions of all these predecessors, there would be little work left for me to do! That is why, when I teach tongue diagnosis, I start from its origins.

Doctor Xu Shuwei’s diagnosis: a white tongue coating — Zhang Zhongjing had said it long ago

History finished, back to the case. Doctor Xu Shuwei looked at Xing Yuanhui’s tongue — a white slippery coating. He said: the pattern of a white slippery tongue coating has several possible situations:

• Some cases have yin and yang pulses both present along with nosebleeds (yin yang mai jie chu bi nü);
• Some are zang jie, an organ binding that cannot be treated — a zang jie condition that can prove fatal;
• Some have heat in the lower elixir field after warming medicine (wen yao hou dan tian you re) — heat inside;
• Some have hardness below the ribs in yang ming disease (yang ming xie xia jian) — the yang ming pattern with hard, full flanks.

Which one was this case? Doctor Xu judged: this case belongs to yang ming.

Why? Because Zhang Zhongjing had discussed it: in yang ming disease, the flanks below the ribs are hard and full, there is no bowel movement, and the patient vomits — when an external pathogen enters and reaches the yang ming state, the flanks are hard, there is no stool, and vomiting occurs: this is qi movement blocked in the upper burner, the disease mechanism stuck there, which is why the flanks are hard, the bowels do not move, and vomiting arises. Zhang Zhongjing then said the famous sentence:

“She shang bai tai zhe, ke yu Xiao Chai Hu Tang.” — “When the tongue has a white coating, Minor Bupleurum Decoction may be given.”

💬 Note from Doctor Luo: What is Minor Bupleurum Decoction for? Harmonizing the qi mechanism and opening the qi. “Shang jiao de tong, jin ye de xia, wei qi yin he” — once the upper burner is free, fluids can descend, and the stomach qi becomes harmonious; then the bowels move. “Shen ji ran han chu er jie” — the body breaks into a gentle sweat, and the illness is resolved. Minor Bupleurum Decoction can treat all three yang patterns — tai yang, yang ming, and shao yang all respond to it. This is the deepest passage on tongue diagnosis in Zhang Zhongjing’s work, and the most famous sentence in the entire literature of Chinese tongue diagnosis.

The treatment: vomit first, harmonize afterward — within days a sweat breaks and the illness resolves

Doctor Xu Shuwei’s treatment proceeded in two steps:

First step: Zhi Zi Tang to induce vomiting (zhi zi tang tu yu qian) — first he used Zhi Zi Tang (Gardenia Decoction) to provoke vomiting, sending the pathogen and turbid phlegm bound in the upper burner upward and out, giving the pathogen an exit;

Second step: Xiao Chai Hu Tang to harmonize (xiao chai hu tang ji yu hou) — then he gave Xiao Chai Hu Tang (Minor Bupleurum Decoction) to harmonize the shao yang and regulate the qi mechanism.

What was the result? Within several days a sweat broke and the illness resolved (shu ri han jie er yu) — after a few days, a sweat came, and the disease was completely cured.

💬 Note from Doctor Luo: This case is recorded very simply, but its significance is enormous — it is one of Chinese medicine’s earliest case records in which tongue diagnosis was used to differentiate and treat disease, earlier than the Yuan dynasty Ao’s Golden Mirror; this is Song dynasty material. Zhang Zhongjing wrote out his formula, but whether later generations used it is unknown — Doctor Xu Shuwei used it for you. By formally raising tongue diagnosis as a subject, he was reminding everyone: tongue diagnosis — you must take it seriously.

Doctor Luo’s specialty: what exactly does the tongue of the Minor Bupleurum pattern look like?

The case is told; Doctor Luo now turns to his own research — what is the tongue picture of the Minor Bupleurum Decoction pattern?

First, a principle: tongue diagnosis develops. It is not the case that whatever the ancients said is final, or that the earliest is the best. Zhang Zhongjing said “when the tongue has a white coating, Minor Bupleurum Decoction may be given” — but there are countless diseases with a white tongue coating; even a healthy person’s tongue may be white. Zhang Zhongjing was only making a description; he did not say white coating equals the Minor Bupleurum pattern. So what is the actual tongue picture of this pattern? This is precisely the direction of Doctor Luo’s research.

💬 Note from Doctor Luo: When I read this book years ago, I kept pondering: Zhang Zhongjing valued this so much and deliberately spoke of the white tongue coating — so what exactly does it look like? I began comparing and researching constantly, and gradually I found it out. This research is the experience I gathered through years of collecting information during my doctoral work.

Please remember Doctor Luo’s conclusion — people with the Minor Bupleurum pattern have a “pointed tongue”:

• Tongue shape: pointed. When the tongue comes out, the tip is sharp;
• Tongue coating: white, often thick. Sometimes dry, sometimes moist, but frequently with a heavy accumulation of coating on top;
• Tongue edges: often red — because there may be liver fire inside;
• This is the appearance of mixed cold and heat with blocked qi movement (han re cuo za, qi ji zu zhi). When the coating is very thick, it often hides the red tongue body underneath, so on the surface all you see is white and thick.

Why do people with a pointed tongue and white coating catch colds more easily?

Now the more important finding: people with this “pointed tongue and white coating” are more prone to externally contracted illnesses than ordinary people!

💬 Note from Doctor Luo: The Minor Bupleurum pattern is the shao yang pattern — disharmony of the liver and gallbladder with stagnant qi movement. But note — you do not have to contract cold damage to enter the shao yang pattern; many people live in this state all the time: one burst of anger, one wave of stress, one bout of qi stagnation, liver-gallbladder disharmony — this is their everyday state. In such people the liver qi is constrained and the qi mechanism is knotted inside; the defensive troops cannot reach their posts in time, so when an external pathogen arrives, others are fine but this person catches a cold. And once infected, such a person is more likely to enter the shao yang pattern — alternating chills and fever, bitter taste in the mouth and dry throat, dizziness, silence and no desire to eat, fullness in the chest and flanks (especially below the ribs), easy irritability, and particular trouble with insomnia and excessive dreaming.

So external infections and everyday internal disharmony feed each other: people with constrained liver qi catch colds easily, and once they catch one they slip more readily into the shao yang pattern; conversely, that constitution further knots the qi mechanism. This is why — emotionally upset people catch colds easily, and some people, after one burst of anger or one wave of pressure, wake up the next morning with a cold.

A discovery from the COVID era: three types of people were the most vulnerable

This understanding was confirmed on a massive scale during the COVID-19 pandemic.

💬 Note from Doctor Luo: During the Wuhan outbreak, a large number of frontline doctors collected tens of thousands of tongue photographs. We have a Tongue Diagnosis Professional Committee on our side, and we analyzed tongue pictures together, discussing them daily. From what I collected, susceptible people fell into roughly three groups: one was the cold type — people whose constitution was already deficient in yang qi; when temperatures dropped they easily caught cold, developing in the cold direction. Another was the fluid-deficient, yin-deficient type — more vulnerable in hot, dry weather. And a very large proportion were exactly the people with a pointed tongue covered with thick, greasy white coating — constrained liver qi and stagnant qi movement.

This is not something that appears only after falling ill; these are the same people in ordinary times. Because all externally contracted illnesses are based on a change in your internal environment — “zheng qi cun nei, xie bu ke gan”: when upright qi (zheng qi) is secure within, pathogenic qi cannot invade. If everything is well inside your body, how could an external pathogen infect you? Among the same group of people, why are some infected and others not? Because the body has entered a different state — a troubled state — and that is what gives the external pathogen its opening.

One glance at the tongue reveals your anxiety: 90% of patients with emotional disorders have pointed tongues

Finally, Doctor Luo teaches everyone a skill for “reading people” — a pointed tongue is often a signal of anxiety.

💬 Note from Doctor Luo: Some practitioners do not understand this and say a pointed tongue shape just means the person extended the tongue with force. No — not everyone who sticks out the tongue forcefully produces a point. If you stick out the tongue casually and its shape is pointed, it shows this person’s mind is in an anxious, tense state. In all my years of observation, more than 90% of people with emotional disorders have a pointed tongue — I call it every time. Just yesterday a friend told me about a relative at home who checks everything every morning, terrified of having some disease, dreading a terminal illness, yet no test finds anything — extremely tense. He sent me a photo of the tongue: when extended it looked round, but in the video, in the instant it withdrew, the tongue turned pointed — I saw it in that split second: this person is anxious. I told him to pay attention to reducing stress, and that evening he replied: you are exactly right, he is under enormous pressure right now, one thing after another.

So from now on you can check for yourselves: stick out the tongue casually — if the tip is sharp, it is basically time to regulate your emotions — even many children show this now.

💬 Note from Doctor Luo: Zhang Zhongjing said “dan jian yi zheng bian shi” — see one symptom and you can decide. When you see a pointed tongue with thick white coating, first consider the shao yang pattern, then ask: is there a bitter taste in the mouth? Is the appetite poor? Any dizziness? Do you dream a lot at night? Match a few, and you are close to certain. Tongue diagnosis provides too little material — I consider that a pity. If through research and pooled experience we can enrich Zhang Zhongjing’s statements, I believe the classical formulas will be applied more widely and more accurately. Let me contribute what I have found: the tongue picture of the shao yang pattern is a pointed tongue, a thick white coating, and red tongue edges. This has diagnostic significance for externally contracted illnesses — and even more so for emotional disorders.

In this case, Doctor Xu Shuwei used a tongue with a white slippery coating to draw out a story of nearly a thousand years of tongue diagnosis. From Zhang Zhongjing’s “when the tongue has a white coating, Minor Bupleurum Decoction may be given,” to Master Ao’s Golden Mirror in the Yuan dynasty, to Doctor Xue Lizhai’s printing and promotion in the Ming dynasty, to the Warm Disease school’s blanket coverage in the Qing dynasty — the knowledge of the tongue was built brick by brick by generation after generation of physicians. And today, one more brick is added: pointed tongue, white coating, stagnant qi movement. For such a person, do not rush to prevent colds — first smooth out the emotions, open up the qi mechanism — zheng qi cun nei, xie bu ke gan: when upright qi is secure within, pathogenic qi cannot invade.

Based on Doctor Luo Dalun’s commentary on Doctor Xu Shuwei’s case record; the case is from Discussion of Ninety Cases of Cold Damage (《伤寒九十论》) by Doctor Xu Shuwei.