Fever at Night, Gone by Morning — a Low Fever That Just Won’t Quit? Doctor Luo Dalun on the Qing-Dynasty Formula Qing Hao Bie Jia Tang (Sweet Wormwood and Turtle Shell Decoction): Nourishing Yin and Drawing the Latent Pathogen Out of the Yin Aspect

Opening: when the epidemic came, Doctor Luo spent his days staring at photos of patients’ tongues

The formula we talk about today was not picked at random — during this period Doctor Luo has been looking at tongue photos sent from the front line every day, sorting the patients by tongue presentation, and then explaining the matching formulas. Qing Hao Bie Jia Tang, today’s subject, is an important member of this epidemic-prevention series.

💬 Note from Doctor Luo: Dear friends, good morning, everyone. Today I will continue with formulas that are useful for this epidemic. The formulas I talk about are not ones I just thought of casually and picked at random. No. Because every day we look at the tongue photos sent from the front line. Based on these tongue photos, we sort out the types and provide this information. I look at the types of tongue coatings, and I tell you: for these types, which formulas can be used? I will introduce them — this is one way of helping.

Where does this formula come from? — the story of a scholar who took up medicine for his father

Qing Hao Bie Jia Tang comes from a celebrated Qing-dynasty medical work — the Systematic Differentiation of Warm Diseases (Wen Bing Tiao Bian) — written by the famous Qing-dynasty physician Doctor Wu Jutong. The reason Doctor Wu took up medicine is a heartbreaking story.

💬 Note from Doctor Luo: The formula we discuss today is called Qing Hao Bie Jia Tang. Where does it come from? In the Qing dynasty there was a famous physician called Wu Jutong, who wrote a book called the Wen Bing Tiao Bian. If you have read what I have written before, you know I have talked about Wu Jutong. Wu Jutong was originally an ordinary scholar preparing for the imperial examinations. Then his father fell ill, the physicians failed to cure him, and he passed away. Wu Jutong felt deeply ashamed and blamed himself. Why? He said: we are all sons of Confucian families — filial piety is the first virtue. Yet when my father died, I did not even know what disease he had — what it was called, what name the illness went by. How can I still hold up my head between heaven and earth? What face do I have to go on living? It is too shameful to live like this.

His father died under the care of an incompetent physician, and he did not even know the name of the disease — this self-reproach became the starting point of Doctor Wu’s medical studies. During the mourning period he bought medical books and began to read, and he read for many years.

💬 Note from Doctor Luo: So during the mourning period for his father, he began buying medical books and reading. And once he started reading, there was no stopping him — he read for many years. Later, when the imperial court organized the compilation of the Siku Quanshu encyclopedia, he went to the capital to help copy texts and organized many students to do the copying. He saw a great many books and broadened his knowledge. In the end he became a great physician — a warm-disease master — and his book was the Wen Bing Tiao Bian.

One book, the Wen Bing Tiao Bian, that explained warm disease clearly

Today the Wen Bing Tiao Bian is counted among the four great classics of Chinese medicine. And the founder of the study of warm disease was the earlier physician Doctor Ye Tianshi — the doctor who lectured to his disciples from a small boat while making house calls, and whose disciples wrote down his words to form a book.

💬 Note from Doctor Luo: The founder of warm-disease study was Ye Tianshi, who wrote the Wen Re Lun (Treatise on Warm-Heat), and what he wrote was extremely simple. Ye Tianshi was very busy — while making house calls he would sit in a small boat and talk with his disciples, and the disciples recorded it, calling the work the Wen Re Lun. What did Ye Tianshi’s Wen Re Lun create? It established the framework of Wei-Qi-Ying-Blood (defense-qi-nutrient-blood) pattern differentiation. Reading it today, every word is a gem — truly extremely refined — but unfortunately it is extremely short. Then Wu Jutong expounded the subject in great detail: he discussed warm disease very systematically and created a Triple Burner pattern system. It is well written and very thorough.

What does it treat? — the “night heat, morning coolness” of late-stage warm disease

So what exactly does Qing Hao Bie Jia Tang treat? In short: in the later stage of a warm disease, when the earlier treatment was not handled well, the upright qi is badly damaged — especially the yin aspect, which is injured severely — and the pathogen has slipped in and hidden itself inside the yin aspect. The typical symptom that appears then is “night heat with morning coolness (ye re zao liang).”

💬 Note from Doctor Luo: What disease does Qing Hao Bie Jia Tang treat? It is like this: after a person contracts a warm-heat epidemic disease, in the later stage the earlier treatment may not have been handled well. In the end the upright qi is badly damaged — especially the yin, the yin of yin and yang — the yin aspect is injured very severely. So this time the pathogen gets in, enters the yin aspect and hides in the yin aspect, and at the same time our yin is very badly injured. What symptoms appear then? It is like this — remember, the first feature is night heat with morning coolness: the person runs a fever at night, the body burns, the fever is heavy at night, and by morning the body cools down. That is its hallmark: night heat with morning coolness. What else? The fever subsides without sweating — in the morning, when the fever breaks, there is no sweat. Some people sweat and the fever breaks and they are no longer feverish, but here the fever breaks without sweat. And the tongue is certainly red — remember, the tongue must be red, with little coating or no coating, and the pulse is thin and beats very fast.

Why exactly “fever at night, breaking by morning”? — a husband-and-wife catching insects as an analogy

Fine during the day, feverish once night falls, then breaking by morning on its own — what is going on? Doctor Luo draws a vivid picture: think of a married couple at home — the wife is yin, the husband is yang.

💬 Note from Doctor Luo: The body’s protective yang qi, the defensive qi (wei qi), travels on the surface of the body during the day; at night it withdraws and stores itself inside. Now your yin aspect has a pathogen hidden in it — the external pathogen got in and there is lurking heat in the yin aspect — so when the yang qi enters at night, what happens? It contends with the pathogen, and the heat flares up. And your yin is already insufficient — normally, when yin and yang are balanced, there is no fever. Your yin is already deficient, so it is what we call “yin failing to restrain yang.” So at night, what happens? At night the heat appears much stronger, and the person starts running a fever — that is the “night heat.” In the morning the yang qi goes outward again, comes out again, so you feel fine — the body seems to have cooled, you feel settled and quiet.

And why does the fever break without sweating? Because the yin deficiency is too severe and the fluids are badly depleted — there is no sweat left to produce. A normal person’s temperature drops with a little sweat; the sweat comes out and the temperature falls. But this person does not even have sweat.

💬 Note from Doctor Luo: Think of it as a married couple, one man, one woman. The wife is yin, the husband is yang. During the day the husband goes out to work; at night he comes home to sleep and rest; the next day he goes out to work again — this is the daily rhythm. The wife’s health has recently declined; she is very weak and can only lie in bed resting. Now insects get into the house — lots of insects, flying around the room. Normally, the wife would get up and the two of them would swat them dead, and that would be the end of it — the battle in the house would be over and life would return to normal. Not now. The wife is lying in bed; she can only endure the buzzing of the insects. The husband comes home from work in the evening, and when he sees the room — he was going to rest, but now rest is impossible. So through the night he starts swatting insects: that is the night heat — heat at night, the battle raging, smoke and dust everywhere. He swats until morning; dawn comes, he has not rested well, and what can he do? He has to go to work. Once he leaves, the wife still cannot swat the insects; nobody is swatting them, and the room temporarily quiets down again. That is “night heat with morning coolness.”

Who tends to end up like this? — a yin-deficient constitution meets pathogenic heat

Why do some people land in this situation from the same illness? Doctor Luo says that after an external pathogen enters, the pattern your body takes depends largely on the state of your own body — constitution, environment, and pathogen all act on top of one another.

💬 Note from Doctor Luo: If a person already has yin deficiency, or a tendency toward yin deficiency, and when the pathogen comes in the external environment also has hot factors in it — then once the pathogen enters, the struggle in our body more easily consumes our yin. What is yin? It is the liquid-type substances — the fluids that govern stillness and moistening, such as jin ye (body fluids) and jing xue (essence and blood); these all belong to yin, the quiet, moistening substances. If the person did not have much of these to begin with, and the external environment is scorching hot, the heat opens the pores and makes things leak, makes you sweat, causing your yin fluids to be lost — your fluids become insufficient. Then when you contend with the external pathogen, what happens? It consumes your yin substances even more, so such a person’s yin deficiency becomes even more severe.

How to treat it? — this time what we supplement is not qi, but yin

Earlier I talked about Ren Shen Bai Du San (Ginseng Toxin-Vanquishing Powder) — that is about supplementing qi: when the upright qi is insufficient and the pathogen has just arrived, quickly supplement qi and fight it outward. Qing Hao Bie Jia Tang takes a different route: the battle has reached its later stage, provisions and ammunition are exhausted, and what needs to be replenished is “materiel” — that is, nourishing yin.

💬 Note from Doctor Luo: So how do we treat it at this point? We certainly still supplement. I have mentioned many supplementation methods before — supporting the upright qi (fu zheng). But here, what we support is the yin. What did the Ren Shen Bai Du San I talked about earlier do? It supplements qi, right? The upright qi is insufficient, the pathogen has just arrived — quickly supplement qi and fight it outward. At the front, the battle has been going on, but later, as the fighting drags on, the supplies run short. The yin fluids — we can compare them to the supplies running short. When the supplies are gone, when there is no grain, no pay, no ammunition — this is already the late stage of the war. The fighting has gone badly, and under these conditions continuing to fight is extremely difficult. So what must be supplemented? Materiel must be supplemented. To support the upright qi, at this point you supplement the material — replenish the yin fluids fully, nourish yin until it is sufficient, and at the same time expel the pathogen. Only then will the effect be good. So it differs from supplementing qi — this one nourishes yin.

Formula breakdown: qing hao paired with bie jia, a golden duo of “entering first, emerging later”

Qing Hao Bie Jia Tang is simple in composition: qing hao (sweet wormwood) 2 qian (6 g), bie jia (turtle shell) 5 qian (15 g), xi sheng di (fine-grade raw rehmannia) 4 qian (12 g), zhi mu (Anemarrhena rhizome) 2 qian (6 g), and dan pi (moutan peony bark) 3 qian (9 g) — five herbs in all. The subtlety lies entirely in the pairing.

First, qing hao — everyone knows this herb now: Tu Youyou extracted artemisinin from it and won the Nobel Prize.

💬 Note from Doctor Luo: Qing hao is a cold herb — bitter in taste, cold in nature. It enters the liver and gallbladder channels. What does it do? It clears heat and resolves summer-heat: if you have pathogenic heat inside, it clears it outward — clearing heat and resolving summer-heat, treating warm disease specifically: bone-steaming tidal fever (gu zheng chao re), malaria, and so on. Its main function is to draw out and release the pathogenic heat hidden in the yin aspect — that is the function of qing hao. As Doctor Wu Jutong himself wrote in his explanation of the formula: “qing hao is fragrant and penetrates the collaterals, leading the pathogen out from the Shaoyang” — that is an extremely famous line. Once Doctor Wu put it that way, everyone remembered it: “leading the pathogen out from the Shaoyang.” Your pathogen must have a way out. A pathogen having no way out — that is not how Chinese medicine treats illness. It is not “annihilate the enemy.” No — the pathogen is regularly shown the door. So where does this formula send the pathogen out? It leads it out from the Shaoyang.

Next, bie jia — the turtle shell of everyday speech, washed clean and dried for medicinal use.

💬 Note from Doctor Luo: Bie jia is the shell of the soft-shelled turtle — you wash it clean, dry it in the sun, and this is bie jia. Its nature is salty and neutral — slightly salty and cold, also cool — and it enters the liver and spleen channels. What does bie jia do? Mainly it nourishes yin and clears heat. Its first function is nourishing yin — it can nourish and support yin. Its second function is clearing heat — it can clear the bone-steaming tidal fever, the deficiency heat caused by yin deficiency; it can calm liver wind; and it can soften hardness and dissipate masses (ruan jian san jie). When we have lumps and masses, we add bie jia — it softens hardness, dissipates masses, and breaks up the lump.

Pair these two herbs together and the magic appears — Doctor Wu’s discussion of it is something every student of Chinese medicine must memorize, because it is so precise.

💬 Note from Doctor Luo: He said qing hao can clear the pathogenic heat of the liver channel — true. But qing hao cannot enter the yin aspect directly; it has difficulty getting into the yin aspect on its own. With bie jia leading it in, however, it gets in. So what does he call this? He calls it “the wonder of entering first and emerging later (xian ru hou chu)” — first enter. Qing hao works upward to draw things out, but it cannot get in; bie jia can go inward. And bie jia cannot leave the yang aspect on its own — it cannot push the pathogen up into the yang aspect. With qing hao to escort it out, though, it can. So he said qing hao and bie jia are like a pair of excellent partners: working together they can search out the pathogen hiding in the yin aspect. That is the particularly delightful part of his explanation.

The remaining three herbs: supporting players, each with their own job

The formula also contains xi sheng di, zhi mu, and dan pi. Xi sheng di has a particular refinement — in ancient times, “sheng di” (raw rehmannia) came in grades.

💬 Note from Doctor Luo: This xi sheng di — I have mentioned it in my audio talks. What is xi sheng di? In the pharmacy today, when you order sheng di, you simply get sheng di. But in ancient times raw rehmannia was divided into several kinds: xi sheng di (fine), da sheng di (large), and xian sheng di (fresh). What does xian sheng di do? It has a heat-clearing action — it draws the pathogen out and clears heat; it clears outward. Da sheng di has an especially strong yin-nourishing action, because it is large and heavy, very strong at nourishing yin. Xi sheng di is the small raw rehmannia — what does it do? It both nourishes yin and draws the pathogen outward, but neither action is as strong as the other two. So in ancient times, if you were treating warm disease and truly needed to draw the pathogen out, you used xian sheng di. If you were nourishing yin and cooling the blood, you used da sheng di. If you wanted both to nourish yin and to draw the pathogen out, you used xi sheng di. That is the fine distinction — hence the name xi sheng di. Today you can simply write sheng di at the pharmacy; when choosing, you can pick the smaller pieces.

And dan pi? That is moutan peony bark, whose special task is to drain the lurking fire in the blood.

💬 Note from Doctor Luo: What does dan pi do here? Moutan peony bark drains the lurking fire in the blood — it drains the heat of the liver channel. Because in this disease the liver stores the blood, and when the yin aspect is insufficient, the pathogen tends to hide in the liver channel, with lurking fire there. So we use dan pi to drain the fire — drain the liver fire. And zhi mu also clears heat.

How to use it today? — lingering low-grade fever, red tongue, thin or absent coating

Put these herbs together, and the power to draw out pathogenic heat is strong; paired with herbs that nourish yin and clear heat, the effect is quite good. Today this formula is widely used for all kinds of fevers.

💬 Note from Doctor Luo: As long as a person has yin deficiency with pathogenic heat inside at the same time, this formula can be modified and used. So today we use Qing Hao Bie Jia Tang broadly for all kinds of fever conditions. Many fever conditions — a lot of mysterious fevers where the person simply runs a fever, a low-grade fever, for no known reason. As long as you look and the tongue body is red — and let me add one more point about this: if such a person runs a fever at night but not during the day, during the day the tongue is not so red. When the fever comes on at night, the tongue becomes very red. So the tongue presentation differs a little between day and night — there is some difference — so everyone must observe carefully.

One yin, one yang: read side by side with Ma Huang Fu Zi Xi Xin Tang

Doctor Luo also offers a particularly flavorful comparison — the Qing-dynasty physician Doctor Liu Baoyi’s Liu’s Selection of Four Physicians’ Case Records notes that Doctor Zhang Zhongjing used Ma Huang Fu Zi Xi Xin Tang (Ephedra, Aconite and Asarum Decoction) to warm the yang and boost the pathogen outward; and the warm-disease school has the same idea.

💬 Note from Doctor Luo: When the Qing-dynasty physician Liu Baoyi wrote the Liu’s Selection of Four Physicians’ Case Records, they discussed this: in ancient times, Doctor Zhang Zhongjing used Ma Huang Fu Zi Xi Xin Tang — xi xin and fu zi — what for? To warm the yang and drag the pathogen, pushing it outward. Now what about warm disease? Think about it — warm disease has this same line of thinking: draw the pathogen out. The pathogen has come in and hidden itself, has it? What do I do? I supplement the upright qi — supplement what? Supplement yin — and push the pathogen outward bit by bit. So this too is a warm-disease strategy, and together with Ma Huang Fu Zi Xi Xin Tang they form one yin and one yang — both lines of thought are extremely meaningful.

What are the results? — front-line doctors used it, and the fever-reducing effect was excellent

This formula is no paper talk — during this epidemic, physicians have already verified its effect in real combat.

💬 Note from Doctor Luo: In this epidemic, some patients were treated with this formula and the results were excellent — the fever-reducing effect was very good. So everyone remember: the indication is certainly a red tongue, a very thin tongue coating, or no coating at all. Some physicians used this formula in modified form, with excellent results — the patient’s fever came down very quickly, and the patient slowly recovered. So these formulas all come from practice. And today we take them back into practice — they truly can solve today’s problems. I have explained this line of thinking for you; perhaps it can inspire you. In the future, if you friends encounter something related, you can know about it. That is all for today. When I have time I will talk more with you about how to protect ourselves. Thank you, everyone. See you next time.

What to take away

1. Recognize the pattern: yin deficiency carrying lurking heat. After a warm disease — or any external-heat illness — if the fever drags on in the late stage with the signature “night heat, morning coolness” (fever heavy at night, cool by morning), fever that breaks without sweating, a red tongue with little or no coating, and a thin rapid pulse, think of the pathogen hidden in the yin aspect. Watch the tongue carefully at night: in this pattern it turns visibly redder while the fever is on.
2. The formula is small, the pairing is everything. Qing hao (2 qian / 6 g) is cold and fragrant and draws the pathogenic heat out from the Shaoyang; bie jia (5 qian / 15 g) is salty and enters deep to nourish yin, soften hardness, and search the collaterals. One cannot enter the yin aspect alone, the other cannot leave the yang aspect alone — together they achieve the “wonder of entering first and emerging later” (xian ru hou chu) and dredge the lurking pathogen out. Xi sheng di (4 qian / 12 g) nourishes yin and draws pathogen outward, zhi mu (2 qian / 6 g) clears heat, dan pi (3 qian / 9 g) drains the lurking fire in the blood and the liver.
3. Why the fever is at night: the protective yang qi withdraws inward at night and contends with the hidden pathogen — heat flares; at dawn the yang qi goes outward again and the heat quiets, so it “breaks” by morning. And it breaks without sweat because the yin and fluids are so depleted there is no sweat to spare — not a sign of health.
4. Read it as the mirror image of Ma Huang Fu Zi Xi Xin Tang. Warming the yang to boost the pathogen outward versus nourishing the yin to draw the pathogen out — one yin, one yang, two complementary strategies for escorting the pathogen out of the body. Choosing between them comes down to the tongue and pulse: pale, cold, and sinking favors warming yang; red, thin-coated, and rapid favors nourishing yin.
5. Modern use. Any unexplained low-grade fever with a red tongue and thin or absent coating can be treated with modifications of this formula — and front-line doctors during the epidemic reported excellent results bringing fevers down and helping patients recover. As with every formula, this is a pattern, not a recipe: when in doubt, consult a qualified Chinese medicine practitioner.

Compiled from Doctor Luo Dalun’s health lecture series (Qing Hao Bie Jia Tang · epidemic-prevention series, formula volume); the formula comes from Doctor Wu Jutong’s Qing-dynasty Systematic Differentiation of Warm Diseases (Wen Bing Tiao Bian).