In Traditional Chinese Medicine, blood pressure is viewed through the lens of imbalances in qi, blood, yin, and yang: high blood pressure is often attributed to “excessive liver yang,” while low blood pressure is often attributed to “deficiency of qi and blood.”
The Story of Washing the Floor
With the Spring Festival approaching, my wife and I were cleaning the floor outside our house. My wife first swept the floor clean, then hosed it down with tap water. Since the water pressure wasn’t strong enough to get the job done, she pinched the end of the hose to narrow the stream. Using the same water, the pressure increased, and the cleaning results improved significantly.
As I helped with the rinsing, I wondered: if the hose gets narrower, the pressure increases—can the blood vessels in our bodies also become narrower?
This led me to think about patients with low blood pressure. In the past, when treating low blood pressure, I used methods to tonify and boost qi to raise blood pressure, but the results were generally mediocre. Often, patients would manage just fine while taking medication, but their blood pressure would drop again quickly once they stopped. Could low blood pressure be related to poor vascular elasticity?
I. Constricting Blood Vessels to Raise Blood Pressure
Most of the body’s blood resides in blood vessels of various sizes. When the heart’s stroke volume per minute remains constant, even a slight constriction of the blood vessels throughout the body should raise blood pressure; conversely, in patients with high blood pressure, dilating the blood vessels throughout the body can lower blood pressure!
Cold-natured substances constrict! Acidic substances can also have a constricting effect!
Consequently, when treating low blood pressure, in addition to using herbs to tonify and lift qi and improve cardiac function, I also incorporated herbs such as Herba Eupatorii, Schisandra chinensis, and Ziziphus jujuba peel. Sure enough, the patients’ blood pressure showed significant improvement, and even after discontinuing the medication, it remained at normal levels for a long time!
Later, when I looked up the literature, I discovered that Herba Heracleoides, also known as “Weakness-Relieving Herb,” is used to treat consumptive diseases. It seems its functions—cooling the blood, stopping bleeding, constricting blood vessels, and raising blood pressure—are closely related!
A 35-year-old female patient had been experiencing dizziness for over three years. During that time, she frequently felt lightheaded and dizzy; when standing up from a squatting position, she would nearly faint. However, she did not suffer from visual spinning, nausea, or vomiting. Her blood pressure was repeatedly measured at around 85/50 mmHg. A complete blood count at the hospital indicated mild anemia. For the past three years, she had been taking herbs to tonify qi and blood, but her condition fluctuated between improvement and relapse. Because her condition had worsened over the past month—with symptoms such as palpitations, fatigue, and shortness of breath that intensified with physical activity—she came to see me. At the time of her visit, she presented with the aforementioned symptoms, accompanied by scanty menstrual flow and soreness and weakness in the lower back and knees. The tip of her tongue was red, with a thin white coating; her six pulses were fine and soft. Her blood pressure was 80/50 mmHg.
The preliminary diagnosis is a syndrome of deficiency-related debility. Treatment should focus primarily on tonifying qi and blood, as well as nourishing essence and replenishing marrow. I prescribed a decoction for her to take continuously for one month, with the instruction to discontinue use during menstruation or when suffering from a cold.
In the formula, red ginseng, astragalus, angelica root, and donkey-hide gelatin tonify qi and blood; Schisandra and Herba Eupatorii constrict the blood vessels; Bupleurum and Cimicifuga lift and raise yang qi. These actions—tonifying, constricting, and lifting—address the issues of qi and blood deficiency and low blood pressure from three angles; Epimedium, Cuscuta, Prepared Polygonum, and Deer Antler Gelatin nourish essence and replenish marrow, resolving the root cause of essence and blood deficiency.
After one week of treatment, the patient’s dizziness improved significantly, and the dizziness she experienced when standing up from a squatting position also lessened. After one month of treatment, her symptoms disappeared; her blood pressure was measured at 110/65 mmHg. The patient reported feeling well, and her menstrual flow was heavier than before. After completing another course of treatment, we met again six months later, and she reported that her condition had been cured and had not recurred.
This case demonstrates that the treatment of low blood pressure should address four key aspects: tonifying qi and blood, constricting blood vessels, enhancing yang qi, and nourishing essence and marrow.
Among these, tonifying qi and blood is crucial. Deficiency of qi and blood is akin to a shriveled water pipe with no water; no matter how much the pipe contracts or narrows, the water pressure remains largely unchanged. When qi and blood are sufficient, blood pressure naturally rises.
Nourishing Blood (Ying) flows within the vessels, while Defensive Qi (Wei) flows outside them; Wei belongs to Yang, and Nourishing Blood belongs to Yin. Nourishing Blood (Yin) serves as the material foundation for Defensive Qi (Wei). By using astringent herbs, one can reduce the conversion of Nourishing Blood (Yin) into Defensive Qi (Wei), thereby consolidating and retaining Nourishing Blood (Yin). At the same time, this reduces the dissipation of Defensive Qi (Wei), leading to increased fullness in the blood vessels.
Elevating and lifting Yang Qi promotes the ascension of the body’s Yang Qi. Since the head is where clear Yang Qi converges, an increase in the ascension of clear Yang Qi naturally leads to mental clarity and relief from dizziness.
From a modern medical perspective, the production of red and white blood cells in the blood depends on the bone marrow’s hematopoietic function. In Traditional Chinese Medicine, it is believed that the kidneys govern the bones, and the bones store marrow. Insufficiency of kidney essence leads to a decline in the bone marrow’s hematopoietic function, manifesting as anemia. Therefore, for patients with low blood pressure and anemia, tonifying kidney essence and enhancing the bone marrow’s hematopoietic function will treat the disease at its root.
The case described above was treated by addressing these four aspects simultaneously—addressing both the symptoms and the root cause—which is why the patient’s condition was successfully cured.
Through the example of hosing down the floor, we have come to understand an important aspect of low blood pressure treatment: the need to constrict blood vessels.
II. Correctly Understanding Tonics
In folk medicine, people commonly classify herbs with astringent properties as “tonics,” such as ginkgo nuts and herba eupatorii. This is because these herbs have constricting effects; when consumed by those with physical weakness, they provide a sense of comfort and alleviate dizziness, leading people to colloquially refer to them as tonics.
In addition to these astringent herbs, there is another category that people also classify as “tonic”: sticky and greasy herbs and foods. For example, people believe that glutinous rice is more nourishing than regular rice, that white wood ear fungus is a body tonic, and that Chinese medicinal ingredients such as prepared rehmannia root, red dates, and donkey-hide gelatin are all excellent for nourishing the blood, and so on.
If we think carefully about glutinous rice, white wood ear fungus, prepared rehmannia root, red dates, and donkey-hide gelatin, they all share a common trait: they tend to be nourishing and sticky. Nourishing and sticky substances can affect the flow of blood and qi; in TCM terms, they are considered viscous. For people with weak constitutions or low blood pressure, consuming these viscous foods and medicines slows the flow of blood and qi, raises blood pressure, and makes them feel more comfortable and energetic. This explains why tonic herbs tend to be “stagnating.” But is it appropriate to consume these sticky and heavy foods and medicines over the long term?
It is definitely not advisable. Long-term consumption of these viscous foods and medicines can lead to illness because the circulation of qi and blood becomes obstructed. Although blood supply to the head may improve, other parts of the body will experience blockages—and blockages are also a form of illness. To ensure tonification without stagnation, or to limit stagnation to a manageable degree, blood-nourishing formulas should be appropriately combined with herbs that promote blood circulation or regulate qi, such as Chuanxiong.
With this in mind, let’s examine the classic blood-nourishing formula—Si Wu Tang (Four Substances Decoction). It consists of Shu Di Huang (prepared rehmannia root), Bai Shao (white peony root), Dang Gui (angelica root), and Chuanxiong (Sichuan lovage). Here, Chuanxiong regulates the flow of qi within the blood, thereby preventing Shu Di Huang, Bai Shao, and Dang Gui from causing excessive stagnation due to their nourishing effects.
This is why clinically experienced practitioners, when prescribing high doses of Shu Di Huang, will combine it with qi-regulating herbs such as Sha Ren and Chen Pi.
This principle applies not only to blood-nourishing herbs but also to qi-tonifying herbs.
Clinically, patients with qi deficiency often experience abdominal distension when taking qi-tonifying herbs such as Astragalus (Huangqi) and Codonopsis (Dangshen). This occurs because the tonifying effect is excessive. In such cases, simply adding appropriate qi-moving herbs—such as Wood Fragrance (Muxiang)—or blood-activating herbs—such as Chicken Blood Vine (Jixueteng)—will prevent the onset of abdominal distension.
III. Treatment of Hypertension
From the above discussion on the treatment of hypotension and our understanding of tonic herbs, two conclusions can be drawn: herbs that constrict blood vessels and those that affect blood circulation can both promote an increase in blood pressure. Following this line of reasoning, if we reverse the logic, might herbs that dilate blood vessels and promote blood circulation lower blood pressure and treat hypertension?
This is indeed the case. Clinically, many patients with high blood pressure—especially those whose primary symptom is elevated diastolic pressure—have essentially normal systolic pressure, typically fluctuating around 140 mmHg, while their diastolic pressure can reach as high as 120 mmHg. Although their blood pressure is very high, these patients do not experience obvious symptoms such as dizziness or headaches. They have underlying conditions such as hyperlipidemia and hyperviscosity. If treatment relies solely on antihypertensive drugs to lower diastolic pressure to normal levels, the patients may actually feel dizzy. This is because elevated blood viscosity impedes blood flow in the body. To ensure adequate blood supply to the brain, the body reflexively raises blood pressure to a higher level, which is when the patient feels comfortable. If antihypertensive medications are taken and blood pressure returns to normal, the body’s reflexive regulatory mechanism is suppressed, leading to cerebral ischemia and hypoxia—which inevitably results in symptoms such as dizziness and headaches.
By using medications that dilate cerebral blood vessels and improve blood rheology to enhance circulation and ensure adequate blood supply to the brain, the body’s own regulatory mechanisms will gradually lower the originally elevated blood pressure, restoring the body’s balance. As blood flow becomes unobstructed, symptoms such as numbness in the hands and feet and weakness in the limbs—which were caused by blood stasis—will also improve.
If the use of astringent and viscous agents to raise blood pressure in patients with hypotension is considered a “tonifying” method, then the use of vasodilators and blood-activating agents to treat hypertension is considered a “draining” method. This interplay of tonification and drainage—treating one condition of deficiency and one of excess—is perfectly demonstrated in the treatment of these two diseases.
IV. The Use of Purgative Herbs Requires Great Care
From the stories and case studies above, we can deduce a principle: “Herbs that promote the circulation of qi and blood have a purgative nature, while those that inhibit the circulation of qi and blood have a tonifying nature.” Understanding this explains why radishes should not be consumed alongside ginseng—since radishes regulate qi and possess a purgative nature, they counteract the tonifying effect of ginseng.
If radishes are off-limits, what about scallions? What about onions? What about dried tangerine peel?
They all have the effect of regulating qi, so for patients with qi deficiency, it is not advisable to consume them while taking ginseng. Of course, when using large doses of qi-tonifying herbs, it is still necessary to consume appropriate amounts of qi-regulating herbs to prevent excessive tonification or stagnation.
A few years ago, it was popular to drink an “appetite-stimulating soup,” whose main ingredients were Guangmu Xiang and hawthorn. After drinking it, people would pass gas continuously; as the flow of qi became smooth, qi and blood circulated freely, and they would feel no more pain or bloating—only comfort—and many internal stagnation-related conditions would be treated. This therapy is excellent for people with stagnant qi, but is it suitable for long-term consumption?
Absolutely not. Many people who drink it for an extended period end up feeling completely drained because their qi has been depleted. Therefore, when taking appetite-stimulating soup over a long period, it is necessary to combine it with qi-tonifying herbs such as Astragalus or ginseng. Only then can qi be regulated without damaging the body’s vital energy.
Herbs that regulate or disperse qi can promote the circulation of qi and blood, and thus have a “purgative” effect; similarly, herbs that invigorate blood and unblock vessels also promote the circulation of blood and vessels, and likewise possess a “purgative” effect.
Understanding tonification and purgation in this way broadens one’s perspective significantly. The purgative methods applied in clinical practice are not limited to laxatives; their scope is actually very broad, with laxatives constituting only a small part of it.
V. The Principles of Tonification and Purgation
Reducing swelling and dispersing nodules, regulating qi and dispersing stasis, invigorating blood and unblocking vessels, transforming phlegm and opening the orifices… In fact, any therapeutic method employed to treat excess patterns can be classified as a purgative method.
Acupuncture also involves tonification and purgation!
The rise and fall of the body’s qi follows a regular pattern, which can be summarized as rising from the left and descending from the right. When viewed from the front, this forms a counterclockwise cycle; when viewed from the back, it forms a clockwise cycle.
Therefore, if a needle is inserted from the front and manipulated in a clockwise direction—which runs counter to the body’s natural qi circulation—this technique obstructs the flow of qi and blood and is classified as a tonifying method; Manipulating the needle counterclockwise, which aligns exactly with the body’s qi circulation and promotes the flow of qi and blood, is classified as the “dispersing” method.
If a needle is inserted into a point on the patient’s back and manipulated clockwise—which aligns with the body’s qi circulation and promotes the flow of qi and blood—it is classified as the “dispersing” method; conversely, manipulating the needle counterclockwise—which runs counter to the body’s qi circulation and obstructs the flow of qi and blood—is classified as the “tonifying” method.
This is a fundamental principle—a rule for a deeper understanding of the tonifying and dispersing methods. It is not only reflected in the treatment of diseases but also manifests in every aspect of life.
The saying “honest advice is hard to swallow” embodies this very principle.
Pleasant words and flattering remarks are of a dispersing nature and offer little help to a person’s growth; harsh words and unwelcome remarks are of a tonifying nature and are beneficial to a person’s growth. Doing things solely according to one’s own whims is “dispersing”; but to temper one’s will, exercise self-restraint, and act only after careful consideration—that is “tonifying”!
This holds true for life, for medicine, and for how we conduct ourselves as people!
Modern people face high stress and have many desires; their wishes are often unfulfilled, leading to stagnation of liver and gallbladder qi. Taking herbs that soothe the liver and regulate qi to disperse this stagnation brings some relief—this is the “dispersing” method; Similarly, singing or warming up one’s voice can also regulate qi and falls under the “dispersing” method, effectively treating qi stagnation; sometimes, indulging in a bit of play according to one’s inclinations can lift one’s spirits and relieve oppression—this, too, employs the “dispersing” method and yields therapeutic results.
Some might ask: Why is promoting blood circulation and unblocking meridians so effective against disease? Isn’t that also a “dispersing” method? Why is it used so widely in clinical practice? Honest advice is good, but it’s hard to swallow—does that mean people should always listen to what’s hard to hear? Shouldn’t they listen to what’s easy on the ears?
This involves the issue of pattern differentiation: “dispersion” and “tonification” must be clearly distinguished before application. Tonification isn’t necessarily always effective, nor is “dispersion” necessarily harmful to the body. One must distinguish between deficiency and excess: treat deficiency with tonification, and treat excess with “dispersion.” For conditions classified as “excess,” the purgative method must be used; for those classified as “deficiency,” the tonifying method must be used.
In clinical practice, most cases are not strictly “excess” or strictly “deficiency,” so incorporating tonification within purgation and purgation within tonification is a common approach. It’s like when you want to criticize someone—you have to offer a few words of praise first, so that the person can accept it with an open mind and without resistance. Similarly, when you want to praise someone, you should point out their shortcomings after the praise, as this is the only way to help them achieve even greater success! However, the application of these techniques hinges on one prerequisite: how to accurately distinguish between deficiency and excess.
To illustrate this principle, let’s look at the following story: A Story About Pulse Diagnosis.
