Asthma Attacks, Panting That Won’t Stop, and Diarrhea You Can’t Control? Doctor Zhang Xichun’s Case Treated with the Single-Herb Yam Drink
What people search for: asthma / panting badly / can’t catch my breath / diarrhea that won’t stop Corresponding medical terms: deficiency-type panting (xu chuan) · deficiency of the lung, spleen and kidney · late stage of a warm disease · the lungs and the large intestine are interior–exterior paired
Opening scene: one bowl of yam water turned around a life-threatening spell of panting
Today’s story is about how Doctor Zhang Xichun treated a patient with a single herb: Chinese yam. We have already told quite a few stories of Doctor Zhang Xichun treating illness with yam. Today’s case is an even more typical one — the patient was a man in his forties who had contracted a warm disease (wen bing). As the illness dragged on, he suddenly began panting so hard he could not control it, and at the same time his bowels let go and he could not control that either. Doctor Zhang Xichun prescribed exactly one herb: yam. Within two days he pulled the man back from the brink of collapse.
💬 Note from Doctor Luo: First, let me answer a question left in the comments from last time: what should you do if astragalus (huang qi) makes you feel hot and irritated? In Doctor Zhang Xichun’s formulas, astragalus is usually paired with zhi mu (anemarrhena rhizome) — zhi mu is a cooling herb, used precisely to restrain the warming, drying heat of astragalus; sometimes he also paired it with xuan shen (figwort root), but in smaller amounts. Zhi mu is the “partner herb” that appears again and again in Doctor Zhang Xichun’s prescriptions. Remember this: whenever you use astragalus, don’t forget to give it a cooling companion.
Who was the patient? — a warm disease, and the fever had mostly broken
The patient was in his forties. What was his illness? It was what the old texts call a warm disease (wen bing). What is a warm disease? In the past this was a general name for externally contracted illnesses — the broad category of diseases in which an external pathogen enters the body and brings fever.
💬 Note from Doctor Luo: The school of warm disease theory was developed fully during the Qing dynasty, though its roots go back much earlier. Chinese medicine teaches that when the body is struck by an external pathogen, it is not always cold pathogen (han xie) — besides cold, there is also warm pathogen (wen xie), which announces itself from the very beginning with hot sensations: a sore throat, yellow phlegm, a hot, painful chest, and then fever over the whole body. Many of the infectious and externally contracted diseases we see today are actually warm diseases, and warm disease theory is used all the time in modern practice.
Before Doctor Zhang Xichun arrived, the man had already been treated by earlier physicians, and the fire of the external contraction had been cleared by eight or nine parts out of ten — the fever was down, the heat was resolved, and various methods were being used to sweep out the lingering pathogen. The illness looked as if it were almost over. And then, suddenly, things went wrong.
How sick was he? — panting above, diarrhea below, both ends failing at once
One day, the patient suddenly developed two symptoms, one below and one above:
Below: his stool suddenly slipped out of control (hua xie) — he could not hold it anymore; whenever the urge came, the stool came, and nothing could stop it.
Above: panting (chuan xi) — he breathed continuously, fast and strained, without a moment’s rest.
💬 Note from Doctor Luo: Here is an important piece of Chinese medicine theory: the lungs and the large intestine are interior–exterior paired (fei yu da chang xiang biao li). The lungs and the large intestine form a paired interior–exterior relationship; when lung qi is not firm, the stool runs loose and uncontrolled. So this man’s panting above and diarrhea below were two symptoms of one connected problem — both came from lung qi not being consolidated and the upright qi (zheng qi) being badly depleted.
Doctor Zhang Xichun felt the pulse. It was extremely weak. Then he pressed the two chi positions (chi mai) — the pulse positions that correspond to the kidneys — and when he pressed down just a little, the pulse could barely be felt at all. What did that tell him? That the man’s upright qi was insufficient, and his kidney qi had been drained right down to the root.
What did Doctor Zhang Xichun think? — the most crucial stroke of the whole case
When the illness had reached this state, how should it be treated? Doctor Zhang Xichun thought of a method — a formula he had used before, to which he had given a special name: the Single-Herb Yam Drink (Yi Wei Shu Yu Yin, 一味薯蓣饮).
💬 Note from Doctor Luo: In ancient times, Chinese yam was called shu yu (薯蓣) — sometimes written shu yu (薯芋) — and only later was it renamed shan yao. Doctor Zhang Xichun called this formula the “Single-Herb Yam Drink” because it contains exactly one herb: yam. He was especially skilled at treating illness with a single herb: raw Chinese yam. Everyone should remember this way of thinking.
The prescription: one herb, eighteen liang of yam in two days
How was the formula used? Raw Chinese yam was used urgently — note that what Doctor Zhang Xichun called “raw yam” (sheng shan yao) means dried yam slices, the kind that must be cut into slices and dried. Each dose used six liang (about 180 g) — already a very large amount — decocted into two big bowls of liquid, to be drunk slowly while warm, like tea: whenever he wanted water, he drank this yam water; when it ran out, he added more water and boiled it again, and drank again.
What was the result? In two days he used a total of eighteen liang (about 540 g) of dried yam slices. After drinking all that yam water, the panting disappeared, the restless thirst was cured, and the uncontrollable loose stools stopped.
💬 Note from Doctor Luo: This case looks simple, but the method is exactly what we have discussed before. When the patient still carried a little residual pathogen from the external contraction and his body was weakened to the extreme, Doctor Zhang Xichun used a single herb — yam water — and in one stroke turned the whole state of deficiency around. What does this show? Chinese yam’s power to tonify the lungs, the spleen and the kidneys is very strong. Learning from the experience of the ancient physicians has benefited me enormously — and now I will tell you a case I went through myself.
Doctor Luo’s own case: his classmate’s brother with asthma, saved by yam water
I once had a classmate in middle school whose older brother suffered from asthma — asthma of many years’ standing, with kidney qi deficiency. How severe was it? Only hormone injections could control it, and they puffed him up — he gained a lot of weight — yet still the attacks would not fully stop. Once, triggered by an external contraction, he had a violent asthma attack, and even the doctors said the man might not pull through. He had become so weak that he could no longer walk.
💬 Note from Doctor Luo: I remember it clearly — he was brought in supported by two people, shuffling in step by tiny step. When I saw him, the situation was indeed very serious: this was caused by an external contraction, and it was severe; even his speech came out in gasps between breaths. What to do? I said: treat the external contraction first, because that works immediately — first remove the “chief culprit,” the external pathogen.
I prescribed a formula for the common cold and told him not to take too much — two or three days was enough. Once the external contraction was under control, he should start drinking yam water.
💬 Note from Doctor Luo: How do you prepare yam water? I used 100 g of dried yam slices — at home you can use 60 g, 90 g or 100 g, a big handful of dried yam slices boiled in water. Throughout the day, whenever you feel like drinking water, drink this yam water instead — no need to force it down; drink when you are thirsty. When it runs out, add water and boil it again. You don’t need to eat the yam slices themselves — the medicinal power has already been extracted into the water, so the slices have done their job.
After a few days of this, the man told me he had recovered remarkably well and could move about without difficulty. In the end he went down to Yunnan to recuperate.
Why can yam cure asthma? — cultivate the earth to generate metal
Why do the ancient texts keep saying that yam can treat asthma? This principle needs to be made clear.
💬 Note from Doctor Luo: Asthma — after the excess pattern of the external contraction, a deficiency pattern very often follows. Yam tonifies the spleen, the lungs and the kidneys: when spleen qi is sufficient, it can cultivate the earth to generate metal (pei tu sheng jin) — strengthen the spleen to nourish the lungs — and only then can lung qi become sufficient; and when lung qi is sufficient, the asthma can heal. So my current practice is: when I meet a true asthma patient — the kind who can hardly get the breath in and whose wheezing sound (xiao ming yin) sounds frightening — and I judge it to be deficiency of the lung, spleen and kidney, I have him drink yam water, and the results are excellent. If an external pathogen is present, treat the external pathogen first.
Bonus: dried yam slices vs. fresh yam — don’t use the wrong one
Let me emphasize one more detail here: why use dried yam slices, and not the fresh yam you buy at the market?
💬 Note from Doctor Luo: Fresh yam works if you eat it, but it is not as strong as dried yam slices. After a medicinal herb has gone through processing (pao zhi) — the traditional preparation methods — its power is strengthened and changed, so I have always advocated using dried yam slices as medicine. And one more thing, a tangent: some people compare yam with cordyceps (chong cao). In my view, dried yam slices have the immediate, decisive force of a great general, thousands of times stronger than cordyceps. Cordyceps, drunk as a tonic, basically does almost nothing; at best you can use a little of it as a supporting ingredient for a minor role in supporting the upright qi. That is my honest opinion.
The Single-Herb Yam Drink, used in combination with proper treatment, can often produce effects you would never have expected. This is the experience Doctor Zhang Xichun handed down to us: boil dried yam slices in water, and you can greatly tonify the lungs, spleen and kidneys and turn around a state of deficiency — if someone in the family has asthma, coughing with wheezing, or chronic illness with a weakened body, this method is worth remembering.
Compiled from Doctor Luo Dalun’s narration of Doctor Zhang Xichun’s medical cases; the original case comes from Yixue Zhongzhong Canxi Lu (Records of Chinese Medicine with Reference to Western Medicine).