Cold in Summer, Sweating Like Rain, Itching All Over? Doctor Zhu Danxi: It’s Blood Deficiency, Not Yang Deficiency — a Siwu Decoction Case
What people search for: afraid of cold in summer / cold and sweating / chills all over / need a cotton coat in summer / itching all over / blood deficiency causing chills
In medical terms: blood deficiency (xue xu) · wrongly warmed as yang deficiency · phlegm-dampness trapping the spleen · interior heat damaging fluids
Opening: in the dog days of summer, a rich man sat shivering in a cotton coat
In the sixth lunar month of the Yuan dynasty in Jiangnan — by the Western calendar already July, the hottest stretch of the year, when the cicadas are loud enough to rattle your ears — a very unusual patient appeared. He was a wealthy Semu (色目) man, nearly sixty years old. In the sweltering heat, he was shaking with cold. He needed his food scalding hot. He wrapped himself in a thick cotton coat. And yet, at the same time, sweat poured off him in sheets — sweating like rain.
💬 Note from Doctor Luo: The Semu were a very special group in the Yuan dynasty. The Mongols divided society into four classes — Mongols, Semu, Han, and Southerners. The Semu were the peoples of the Western Regions, second only to the Mongols in rank; those who lived in the south were almost all officials or very rich — the ruling class. This rich man lived in luxury, ate beef and mutton every day, and grew very fat — in the original text, “his form was plump and his flesh thick” (形肥而厚). In a few strokes, Doctor Zhu Danxi tells you everything about this man.
Who was the patient: pampered, and fed into a “rich man’s disease”
The patient’s body was extremely obese, his flesh thick. Why was he fat? The minority peoples loved beef and mutton, and as part of the ruling class he ate supremely well — rich, fatty, sweet food day after day. Of course he grew fat.
Being fat was a signal then, and it still is today. Eat too well and phlegm-dampness (tan shi) builds up; phlegm-dampness traps the spleen and stomach, and the spleen and stomach get hurt — “eat beyond measure, and the spleen and stomach are injured” (饮食自倍，脾胃乃伤). Once the spleen and stomach are injured, they can no longer transform what you eat. Nutrients stop becoming qi and blood — and blood, precisely, is what the spleen and stomach make by transforming the nutrients in food. Injure the spleen and stomach, and the source of blood is cut off.
💬 Note from Doctor Luo: Although Doctor Zhu Danxi was writing about a Yuan-dynasty patient, he was really writing for people of today. How many people now spend every day on rich food and business dinners, eating themselves fat and weak at the same time? The logic is identical: eat too well → phlegm-dampness traps the spleen → spleen and stomach injured → blood deficiency.
How sick was he: afraid of cold in June, after twenty-plus doses of aconite
In the Jiangnan heat of June, he was so cold he needed hot food and a padded coat. To anyone’s eyes that looks like yang deficiency — surely. So the previous doctor prescribed Fuzi (aconite, 附子), the great warming herb — and he took it for twenty-plus doses.
The result? Fuzi warms yang, and it drove the sweat out even harder — he sweated like rain. Sweating this much severely damages the body fluids; yin fluids are lost, the skin loses its moisture, and the whole body starts itching. Feel the pulse: both hands were deep and choppy (chen se, 沉涩) — qi and blood insufficient; press a little harder and the pulse swells — there is heat inside.
💬 Note from Doctor Luo: Blood and sweat share the same source — sweat is transformed from blood. Fuzi forcibly warms the yang and forces the sweat out in a torrent; the more yin blood is drained, the worse the disease becomes. You see — when you misread the direction, the medicine does real damage.
The key diagnosis: Doctor Zhu Danxi saw it in a glance — severe heat with blood deficiency
After examining him, Doctor Zhu Danxi rendered his judgment: severe heat with blood deficiency (热甚而血亏). This man had two problems. First: rich food every day, so there was heat in his body — and the heat ran deep. Second: the spleen and stomach were injured and the source of blood was exhausted — his blood deficiency was severe.
Why does blood deficiency make you cold? Because blood is warm. Blood carries heat around the body, delivering warmth to the limbs and every extremity. When blood is deficient, less of it reaches the hands and feet, and you naturally feel cold.
💬 Note from Doctor Luo: Many women are especially sensitive to cold, and the moment they feel cold they assume yang deficiency and rush to warm the yang — not necessarily! Yang deficiency is only one kind. Blood-deficient coldness is extremely common. Then there are people with heavy phlegm-dampness, or with blood stasis blocking the channels — when circulation is poor, you also feel cold. If you feel cold even in summer, and the cold is obvious, often the phlegm-dampness is heavy and the qi and blood are badly blocked — this man is the classic example. One more reminder: when there is heat inside the body, it can also show up as a false coldness. I once told the story of my mother’s kidney disease as an example — people with heat inside can also feel cold; once the heat is cleared, they stop feeling cold and return to normal.
The prescription, broken down: Siwu Decoction minus Chuanxiong, doubled Shu Dihuang, plus three spleen-nourishing herbs
Doctor Zhu Danxi’s approach was beautifully simple: Siwu Decoction (Four Substances Decoction, 四物汤) minus Chuanxiong. Siwu is the master formula for nourishing blood — Shu Dihuang (prepared rehmannia), Danggui (Chinese angelica), Baishao (white peony), and Chuanxiong (ligusticum). Chuanxiong is slightly drying, so out it goes; Shu Dihuang is doubled to strengthen the blood-nourishing power.
Then he added Baizhu, Huangqi, and Renshen to tonify the spleen and qi, plus stir-fried Huang Bai (phellodendron) to clear damp-heat, and Gancao (licorice) to harmonize all the herbs.
💬 Note from Doctor Luo: Notice Doctor Zhu Danxi’s distinctive claim — he regarded Renshen and Baizhu as blood-nourishing herbs. Later generations usually think of Renshen and Baizhu as spleen- and qi-tonics; but tonifying the spleen is nourishing the blood: when the spleen and stomach are strong, they transform the nutrients in food into blood, and the blood is naturally sufficient. Look at Guipi Tang (Spleen-Returning Decoction) — it is built on Sijunzi Decoction plus Huangqi, Suanzaoren, and Longyanrou, and in formulary textbooks it is classified under blood-nourishing formulas, not qi-tonics. You have to be familiar with this way of speaking when reading Doctor Zhu Danxi — he often used Renshen and Baizhu as yin- and blood-nourishing medicines.
And what is the stir-fried Huang Bai for? Doctor Zhu Danxi had a single-herb formula called Dabu Wan (Great Tonifying Pill, 大补丸) — just stir-fried Huang Bai ground into powder and made into pills, devoted to clearing damp-heat in the lower burner. His Dabu Yin Wan (Great Yin-Tonifying Pill, 大补阴丸) follows the same idea. This man had damp-heat inside; clear that heat away, and he would stop feeling cold — a completely different matter from yang-deficiency coldness.
The twist: one dose in, and the diarrhea was apocalyptic
The medicine weighed two liang (about 60 g) per day — a heavy dose. The first dose went down, and the patient suffered a violent purge of the bowels — so violent that his vision blurred and he could not even speak — in the original text, “mu hun kou jin” (目昏口噤, eyes darkened, mouth locked).
Any ordinary practitioner would have thrown the medicine away in fright. Doctor Zhu Danxi, however, kept his composure and analyzed: the heat in this disease runs very deep, and the medicine was being “rejected” by the body — in his words, it lacked a “counter-assistant” (fan zuo, 反佐). The heat pathogen is deep and fierce; when you send a cooling medicine in, water and fire clash, and the body refuses it.
What to do? Stir-fry the herbs — use the fire of the preparation itself as a guide. The heat pathogen sees something hot arriving, thinks it is one of its own, and accepts it. The medicine slips in with the current, and only then clears the pathogen out.
💬 Note from Doctor Luo: My own reading is that the direction of the formula was right — the body, its upright qi now strengthened, had begun to scour out the phlegm-dampness and expel the garbage; only the dose was indeed large and the action too fierce. After stir-frying, the action softens and the body accepts it. Two readings exist; Doctor Zhu Danxi is the master and it was his method that cured the case, so his account takes priority.
The result: diarrhea stopped after one dose, spirits after four, full recovery after ten
After the herbs were stir-fried and retaken, the diarrhea stopped with the very first dose; after four doses his spirits were back; after ten, the illness was entirely cured. Blood nourished, spleen and stomach strong, phlegm-dampness resolved, upright qi able to circulate through the whole body — naturally, the cold vanished.
💬 Note from Doctor Luo: This case is recorded in Doctor Zhu Danxi’s Ju Fang Fa Hui (Exposition of the Formulary of the Bureau, 局方发挥). When I was a student, I learned by reading the classical doctors’ books one by one, and I met this case early on. But it was only as I grew older and came back to it that I truly understood Doctor Zhu Danxi’s brilliance — he grasped the essentials: blood deficiency; and why blood deficiency? Insufficiency of the spleen and stomach; and underneath, phlegm-heat. The prescription is simple and direct: Renshen, Baizhu, Huangqi, a touch of Chenpi, plus Siwu Decoction, with a little Huang Bai to clear damp-heat. That is a master at work.
What to take away: fear of cold doesn’t always mean yang deficiency
The one sentence from this case worth remembering above all: feeling cold is not necessarily yang deficiency.
Fuzi warms yang — nothing wrong with that, in the right patient. For someone who is truly yang deficient, dried ginger and Fuzi are correct. But for the yin-deficient, blood-deficient, liver-fire-blazing, or phlegm-heat-heavy patient, Fuzi is pouring oil on the fire — it backfires. Zhang Zhongjing’s Shanghan Lun (Treatise on Cold Damage) is a vast work, and it does not treat every disease with dried ginger and Fuzi — it also contains Baihu Tang (White Tiger Decoction) and a whole range of formulas. Chinese medicine is about bian zheng lun zhi — differentiating the pattern to determine the treatment.
💬 Note from Doctor Luo: When I was in school I once read a post by a woman living in America. The air conditioning had chilled her to the bone — several quilts, several pairs of socks, and still her whole body shook. She went to a very famous Chinese medicine doctor in the US, who gave her large doses of Fuzi. It did nothing; she still felt cold. Even that famous doctor finally had nothing more to say. My immediate thought was: this is probably blood deficiency — nourish the blood and she might well recover. Sadly, an ocean lay between us and I could not reach her. There are very many women like her. When you feel cold, first ask whether the blood is deficient — and nourishing the blood starts with regulating the spleen and stomach. Doctor Zhu Danxi’s case here is the best demonstration.
Bonus: diarrhea and fever after taking herbs — don’t rush to stop
Finally, Doctor Luo Dalun shared a piece of insight about medicinal reactions: in this case, Doctor Zhu Danxi let the diarrhea run for one day and then it stopped. In my own view, two more days of purging — letting more phlegm-dampness drain out — would have been even better. So why did it not run longer? This patient was a wealthy Semu, a member of the ruling class — not someone to offend. Purge him too long and there might be trouble. Every case record carries its own background.
💬 Note from Doctor Luo: Many reactions to Chinese herbal medicine are actually good signs. Tonify the spleen and stomach, and the person with heavy cold-dampness will start to pour diarrhea — that is the spleen and stomach waking up and doing the first job: throwing out the garbage. That diarrhea is something to be grateful for. Some people, after taking qi-tonifying medicine, actually develop a fever — that is because they usually lack the strength to fight off pathogens; once the upright qi is sufficient, the body starts driving the pathogens out, which is also a good sign. Unfortunately many patients cry “the prescription is wrong” the moment they see a reaction and stop the medicine at once, missing the window in which the body was readjusting — the phlegm-dampness stays inside forever and never comes out. This is something you really have to learn.
Compiled from Doctor Luo Dalun’s explanation of a case by Doctor Zhu Danxi; the original case appears in Ju Fang Fa Hui (Exposition of the Formulary of the Bureau).