Cough Every Winter That Won’t Go Away? Doctor Wu Jutong’s Case of Latent Summer-Heat

Patient search terms: winter cough / coughs every winter / chest tightness / cough that won’t go away / pain in both flanks when coughing Medical terms for the condition: fu shu (伏暑, latent summer-heat) · damp-heat harbored internally · xuan yin (悬饮, suspended fluid — dampness lodging beside the ribs)

Opening: The fever is gone — but do you really think the pathogen left?

Since the pandemic, many people have had this experience: the fever breaks, and the person seems to be recovering — and yet the illness lingers on: fatigue, and all kinds of small complaints. It’s not quite recovered, but it’s not a fever anymore either.

💬 Note from Doctor Luo: Modern testing now also finds that long after someone has been ill, fragments of the virus can still be detected replicating quietly in the body. How does Chinese medicine explain this? The pathogen is still hiding! That’s why so many people cough for a long time — a few coughs every day, plus all sorts of lingering symptoms. This is the ancient Chinese-medicine concept of fu xie (伏邪), the latent pathogen — a pathogen that has gone into hiding. This idea is especially important for treating externally contracted illness today.

The ancient physicians analyzed these problems more thoroughly than we might imagine. The story today is about exactly this “hiding” — it is a case of latent summer-heat (fu shu) treated by the great warm-disease master Doctor Wu Jutong (吴鞠通).

What is latent summer-heat? A root planted in summer, erupting in autumn or winter

Doctor Wu Jutong, master of the warm-disease school and author of Wen Bing Tiao Bian (《温病条辨》, Systematic Differentiation of Warm Diseases) — a book some scholars say should be counted among the four great classics of Chinese medicine — wrote about latent summer-heat in extraordinary detail.

💬 Note from Doctor Luo: Strictly speaking, latent summer-heat (fu shu) is an illness contracted in the long summer season — the tail end of summer, when dampness is heavy, the weather is sultry, and heat and damp fill the air. When a person’s upright qi is insufficient and they are touched by the summer-heat qi, the heat enters the body without being expelled in time — it goes into hiding. Then when autumn arrives and the weather cools, the lung metal comes into season; the lungs are cool by nature and try to push the heat outward — the body starts to fight, and illness erupts. If the upright qi is even weaker, the illness waits until winter. So the strict definition of fu shu is: contracted in the long summer, erupting in autumn or winter. Broadened a little, any illness with this quality of hidden heat can be called fu shu.

Who was the patient? A 64-year-old gentleman whose root of disease lay in summer

On the 16th day of the ninth month of the yichou year (1805), an elderly Mr. Xing, age 64, came for consultation. His complaint? A cough in winter.

💬 Note from Doctor Luo: Where was the root of this cough? He had not just caught cold! Doctor Wu Jutong judged that this man had been injured by dampness in summer — in the long summer season the damp-heat had been fierce, it had wounded him and lain hidden, and when winter came it erupted as a cough. This is the classic way latent summer-heat presents.

When Doctor Wu Jutong felt the pulse — all six positions wiry — he said one key sentence: wood thriving attacks earth (mu wang ke tu).

The diagnostic highlight: wood attacks earth — but with a coating this white, how can it be heat?

What does “wood thriving attacks earth” mean? The liver fire is strong and the liver qi is not free-flowing — the liver belongs to wood, the spleen and stomach to earth, and the liver qi sweeps across horizontally to bully the spleen and stomach.

💬 Note from Doctor Luo: When the spleen earth is attacked, the result is loose stools; when the stomach earth is attacked, the result is “no appetite and a tendency to vomit” — not wanting to eat, and feeling a little nauseated. Remember: when you meet this combination — no appetite plus a queasy feeling — think of this pattern. This gentleman had also been distended in the abdomen before, and now his chest was stuffy and oppressed (pi men) — the chest feels full, the qi won’t circulate. Looking at the tongue: white, slippery, and thick — by the book, that sounds like cold-damp, doesn’t it?

But here was the strange part: the pulse was actually rapid (shu), and he wanted cold drinks and sour food.

💬 Note from Doctor Luo: This is a contradiction! A white, slippery coating should mean cold-damp; but a rapid pulse — a fast pulse usually means heat, or great deficiency — and a craving for cold drinks: a cold-damp person should want hot water instead. Doctor Wu Jutong said this is what is meant by “when a thing reaches its extreme it reverses” — where there is truth there is also falsehood: the white coating is a false appearance; inside there is really heat! He also specifically warned the patient: above all, guard against anger — do not get angry, it does this illness no good at all; be cautious and careful, because this pattern is complex.

The prescription unpacked: dampness and heat are like oil and flour — drain dampness first, add only a little heat-clearing

With true and false, cold and heat all mixed together, how did he treat it? Doctor Wu Jutong’s prescription was almost entirely dampness-draining — he hardly touched the hot-natured herbs.

💬 Note from Doctor Luo: The ancients described the relationship between dampness and heat as oil mixed into flour — inseparable, and very hard to remove. How do you get rid of it? Dampness is substantial; heat and cold are insubstantial — once you remove the dampness, its carrier is gone and the heat disperses on its own. So in treating damp-heat, you work the heat-clearing and dampness-draining herbs together, first separating the dampness from the heat — then it is no longer sticky and tangled, and much easier to cure.

Look at the prescription and you can already tell its character: it is fairly neutral — not veering violently toward cold or heat, leaning just slightly warm. First go after the dampness:

• Ginger-prepared pinellia (jiang ban xia) — transforms phlegm, drains dampness, sends the stomach qi down, settles that queasy feeling, and opens the chest;
• Refined talc (fei hua shi) — clears heat and drains dampness, tipping the damp-heat out through the urine;
• Raw coix seed (sheng yi ren) — drains dampness from the spleen channel;
• Apricot kernel paste (xing ren) — opens the lung qi; when the lungs open, dampness throughout the body disperses;
• White cardamom kernel (bai kou ren) — opens the qi of the middle burner, the spleen and stomach;
• plus inula flower (xuan fu hua) (descends qi, drains water), turmeric (guang yu jin) (regulates qi), poria peel (fu ling pi) (drains water-dampness), white cardamom peel (bai kou pi) (vigorates the spleen and stomach qi), and rice-paper pith (bai tong cao) (drains dampness and clears heat).

💬 Note from Doctor Luo: Do you see it? This is the San Ren Tang (Three Kernels Decoction, 三仁汤) strategy — apricot kernel opens the upper burner, white cardamom kernel opens the middle burner, raw coix seed opens the lower burner — treating the three burners separately. Doctor Wu Jutong is the man of triple-burner pattern differentiation. The whole prescription, before worrying about cold or heat, first removes the dampness. Five cups of water decocted down to two cups, the dregs re-decocted to one more cup, taken in three portions.

The twist (one): September 18 — the heat surfaces! The white coating really was a false face

The prescription was given on the 16th; on the 18th he returned: the pulse was jumping — extremely rapid (mai su shen) — and he wanted cold drinks. A little dampness had been removed, and the heat showed itself.

💬 Note from Doctor Luo: Why was the tongue coating white before? When dampness is heavy, the heat is concealed underneath; sometimes there is so much dampness that it canopies over the heat — you look and see a field of white, as if the person had caught cold — but in fact he hasn’t! At times like this you must look through every gap: check the underside and the sides of the tongue — is it red? Often it is very red — the heat is tucked under the thick coating. Then look at the whole picture: is the body unusually hot? Is the pulse rapid? A rapid pulse proves heat. This is an extremely easy place to make a mistake.

Doctor Luo Dalun once told of his own student-day experience with exactly this:

💬 Note from Doctor Luo: I caught a cold myself. I looked at my tongue — white, white — and said, “caught cold, right?” There was even a slight sweat, so I took Gui Zhi Tang (Cinnamon Twig Decoction) — and it did nothing. I was puzzled: the tongue so pale and white, why wasn’t the cinnamon decoction working? I looked more carefully — the underside was red! So I took San Ren Tang, and immediately my whole body broke into a sticky sweat, the fever fell, and the illness was cured. It was the most memorable misdiagnosis lesson of my student years.

So the second prescription: increased doses of refined talc, coix seed, poria peel and apricot kernel paste, with scutellaria (huang qin) added — the heat-clearing power was stepped up.

💬 Note from Doctor Luo: When dampness and heat are wrapped up together, adding heat-clearing herbs alone won’t work — the dampness sticks inside; you must put your main effort into draining dampness, and add just a little heat-clearing, and the heat scatters at once. When I prescribe San Ren Tang myself, I always match it with a little honeysuckle, forsythia and scutellaria — the effect is excellent. Doctor Wu Jutong’s prescription here is exactly San Ren Tang as the base plus scutellaria, with rice-paper pith to drain the dampness out through the urine, and patchouli stem and immature bitter orange to regulate the qi and unload the water-dampness of the middle burner.

The twist (two): September 20 — the medicine made him uncomfortable? Long illness, weak constitution, cannot tolerate opening and draining

On the 20th he returned: the patient said that after taking the medicine he actually felt unwell.

💬 Note from Doctor Luo: Usually after drinking San Ren Tang, a person breaks out in a sticky sweat and feels wonderfully light. Why was this gentleman uncomfortable? Doctor Wu Jutong said: “Long illness leaves the body weak; it cannot tolerate opening and draining” (jiu bing ti xu, bu ren kai xie) — his body was too deficient; as soon as the qi was opened and the water drained, he could not bear it. And note this: “One who thirsts is alive; but if he drinks and then stops, that is water settling” — he wanted to drink, yet after a sip he didn’t want more; that too is a sign of retained dampness. Fire and dampness — you cannot attend to only one side.

So the third prescription increased the heat-clearing: raw gypsum 6 qian (18 g), stir-fried anemarrhena, scutellaria, apricot kernel paste — the cooling herbs came up, and the dampness-draining herbs were greatly reduced. Decocted to three cups, taken in three portions. On the 22nd he returned again: the same prescription minus white cardamom kernel, plus patchouli stem and anemarrhena, plus more refined talc and rice-paper pith, taken in four portions.

💬 Note from Doctor Luo: Do you see it? Treating this illness, Doctor Wu Jutong went layer by layer: first drain dampness, adding heat-clearing a little at a time; only when the dampness was mostly gone did he boldly bring in raw gypsum to clear the heat. Why not use gypsum from the very start? Because of the danger of “freezing” (bing fu)! When dampness and heat are mixed, if you hit them immediately with large doses of icy, cooling herbs, the heat is not cleared — instead the dampness increases. That is called bing fu — ice-freezing. Once frozen in, the heat can never disperse; the deeper it stagnates, the more the illness drags on without healing. This is the most exquisite point in treating externally contracted illness.

The twist (three): September 27 — coughing pulls at both flanks — suspended fluid!

On the 27th he came again: the hidden pathogen was rising rebelliously; the heart fire could not descend to communicate with the kidneys, and instead flared upward into the throat — the throat was extremely dry. By this point the illness was actually no longer severe — just a little dampness remained. The new trouble was: every cough tugged and hurt in both flanks.

💬 Note from Doctor Luo: When a cough goes on for a long time, have you noticed — each cough pulls at the flanks, pain on both sides? This is called xuan yin (悬饮, suspended fluid) — dampness lodged inside. In modern terms: intercostal neuralgia! Some people cough so hard that every cough makes the ribs seize up in pain — very miserable. What to do? Add qi-regulating herbs: ginger-prepared pinellia, apricot kernel, immature bitter orange, poria, patchouli stem, and inula flower (xuan fu hua) — inula is the flower that sends qi downward (of all flowers, only inula descends), carrying the dampness down with it; add aged tangerine peel (chen pi) and perilla seed frost (su zi shuang) — draining dampness and regulating qi at the same time.

The close: urine flows, the qi mechanism settles — eight doses, and it was cured

On the 2nd day of the tenth month, urination became difficult — the prescription was augmented with refined talc, raw coix seed and rice-paper pith; altogether he had taken eight doses. On the 6th day of the tenth month, the urine was flowing again — talc, rice-paper pith and coix seed were removed, and a few more doses were taken — complete recovery! Only the little after-effect remained (the cough that pulled at both flanks); once the qi was regulated, a few more doses settled that completely too.

💬 Note from Doctor Luo: Look at how Doctor Wu Jutong practiced: round after round, visit after visit, this is how externally contracted illness is treated. In the old days the patient did not go to the clinic — the doctor went to the patient’s home, every other day. That is how ancient medicine was practiced.

What to take away: damp-heat illness — remember these three things

What does this case teach us? When treating summer-heat and latent summer-heat, draining dampness is the first principle:

💬 Note from Doctor Luo: First — when you see a thick white tongue coating, don’t rush to say “caught cold.” Look at the underside and edges of the tongue — are they red? Is the pulse rapid? Do the eyes and nose feel as if they are on fire? When dampness is too heavy it canopies the heat; the heat cannot show itself, so the coating stays white; when the heat comes out, the coating turns yellow. Second — San Ren Tang (Three Kernels Decoction): this is Doctor Wu Jutong’s own formula, an important prescription in the formulary textbooks of Chinese medicine colleges. It works on damp-heat like a charm — usually once the dampness goes and the heat goes, the fever falls and the person is well at once. Third — the order of operations: clear the dampness first; once the dampness is mostly gone, clear the heat — and it falls away in one sweep. Whatever you do, don’t “freeze” the heat right at the start. And one summary line: cold-damp calls for Huo Xiang Zheng Qi San; damp-heat calls for San Ren Tang — master these two prescriptions, one cold, one heat, and dampness-related illnesses become manageable.

Compiled from Doctor Luo Dalun’s commentary on Doctor Wu Jutong’s case records; the case is from the latent summer-heat (fu shu) chapter of Wu Jutong’s Case Records (《吴鞠通医案》).