Taste, Temperature, Channel, & Direction - Basic Properties of Herbs in TCM | Intro to Herbology

Hey, this is Nicholas. Let's talk about the properties of herbs, like temperature, taste, entering channel, and direction. So first we should ask, why do we even need to know this? Is it just because Chinese medicine teachers are mean and like to torture you by making you memorize a bunch of useless information? Well, maybe. But really, understanding these basic properties is our first step towards understanding how these herbs work, what they can do for us, and how we can use them to treat our patients. Because Chinese herbology isn't like Western herbology. With Western herbs, we tend to take an herb and match it to a symptom. So ginger is good for upset stomach, chamomile is good for insomnia, ginkgo is good for memory, and St. John's Wort is good for depression. But that's not how Chinese medicine works. In Chinese medicine, we're not treating symptoms, we're treating patterns of disharmony. So what do we mean by patterns of disharmony? Well, these are things like liver chi stagnation, kidney yang deficiency, damp heat in the lower jowl. So these patterns describe an imbalance or a disharmony in the normal functioning of the body's systems. So by understanding the nature of these herbs in terms of taste, temperature, entering channel, and direction, that can give us some insight into how these herbs can work to restore balance and ultimately heal our patients. So maybe the simplest to understand is temperature. Each herb is assigned a temperature, also called the chi of an herb. So an herb can be hot, warm, cool, or cold. And then as a fifth one, we can also say an herb is neutral in temperature, or that its chi is balanced. So even though we say the four chi, there are actually like five temperatures. So this gives us a very basic treatment principle Chapter 74 of the Ling Xu states hot diseases must be cooled, cold diseases must be warmed. So basically, if a person is hot, give them cold herbs. If a person is cold, give them hot herbs. Now admittedly, sometimes it gets more complicated than this. People aren't always just hot or just cold. We might see more complicated patterns where there's a mix, like heat above and cold below, cold on the exterior with interior heat, or false cold with true heat. So in situations like this, where you have a combination of both heat and cold in the body, we might end up combining both hot and cold herbs together in a formula. And then we'll just direct those herbs to different parts of the body. And that's something we'll talk more about later. But for now, hopefully this idea of For example, we have common spices like cinnamon, ginger, nutmeg, and clove, and these are all warm in temperature. That's why we eat them during the winter in things like apple pie or pumpkin spice lattes. Things like watermelon and mint, on the other hand, are very cooling in temperature, and that's why we eat them during the summer. Watermelon is very cooling and refreshing, so if you eat it during the winter when it's cold outside, people are going to look at you funny. So that's the idea of temperature, and it's one of the basic things we want to keep in mind when describing herbs to our patients. The next thing we want to talk about is the five tastes, or the five flavors, which are sour, bitter, sweet, acrid, and salty. So each herb will have one or more of and the flavor of an herb will determine what action or effect it has on the body. So let's go through them one by one. So with sour, we say that the sour flavor induces astringency. But what does that even mean, induce astringency? No, not that. When we say induce astringency, we mean that these herbs prevent or stop the abnormal leakage of chi and fluids. So, more simply stated, sour herbs stop leakage. Remember in fundamentals class, we learned the five functions of chi. Well, one of those functions was containment. Chi is supposed to contain and hold things in place. When chi is deficient and fails in its function of containment, then things leak out. What does this leakage look like? Well, we could have leakage of fluids, like spontaneous sweating, night sweats, incontinence, bedwetting, or frequent urination. We could have leakage of chi, like with chronic cough. Here we would say this is the lung chi leaking out. We could have leakage of essence, like seminal emission or vaginal discharge. Or we could even have large intestine leakage, such as chronic diarrhea. So herbs with a sour flavor can be used to prevent or stop these types of leakage. Another phrase we use here is stabilize and bind, and that's just another way of saying stop leakage. I just want to bring this up here because this is the name of the category in Bensky, herbs that stabilize and bind, and this is just a category of herbs that stop leakage. The thing we want to be careful of, though, is that these herbs are for chronic long-standing cases due to deficiency, where chi is failing in its function of containment. So if we have chronic long-standing diarrhea due to spleen chi deficiency, then we can use sour herbs to stop the diarrhea. However, if we have an acute case of diarrhea due to an excess damp heat pathogen, then we would not use sour herbs. In that case, using sour herbs would just trap the pathogen inside the body, and that's not what we want. So next is bitter. Bitter herbs have two functions. They clear heat and drain fire, and they dry dampness. Now here, some people like to ask, what's the difference between clearing heat and draining fire? Well, the answer is, not much. If you want to be real nitpicky, you can look at Nigel Weissman's Practical Dictionary of Chinese Medicine, where he says, fire denotes a form of repletion heat arising from the transformation of other evils and from the transformation of yang chi. But, on the other hand, I've had Chinese teachers tell me that the only reason we say it this way is because in Chinese, things sound more poetic when you use four characters. So when you say it this way, qing zhi xie huo, it just sounds more beautiful. But then, we can maybe also say that the word draining implies that bitter herbs have a downward direction. For example, dahuang drains heat and fire downwards to relieve constipation. But, however you want to say it, I think the important thing to remember is that bitter herbs are good for getting rid of heat in the body. Besides that, the bitter flavor also dries dampness. So we can combine this function with the first one and say that bitter herbs are good for damp heat. But, we also have bitter herbs that treat cold damp as well. So don't get confused. Just because we say that one function of bitter herbs is that they clear heat and drain fire, that doesn't mean that all bitter herbs are cold in temperature. We do have herbs that are bitter in flavor and warm in temperature, and that just means they're using the second function of the bitter flavor, which is drying dampness. Next, we have sweet herbs. Sweet herbs tonify and moisten. So anytime we're dealing with deficiency, whether it's qi deficiency, blood deficiency, yin deficiency, or yang deficiency, we tend to use herbs that are sweet in flavor. One thing we might want to worry about though is that sweet herbs tend to be rich and cloying and difficult to digest. So taking a lot of sweet herbs can very easily cause stagnation. So when we take sweet herbs, it's very common to combine them with herbs that have a moving property as well. And that brings us to the next flavor, which is acrid. The acrid flavor moves and disperses. So anytime we're dealing with stagnation, whether it's qi stagnation, blood stagnation, or stagnation due to cold, we'll use acrid herbs to move and disperse. And then when we say that acrid herbs disperse, that also means that they disperse outward to expel pathogenic influences from the exterior levels of the body. So we can also say that acrid herbs promote sweating to release the exterior. So the actual taste of acrid can be kind of difficult to explain. Some other translations we use are But we don't necessarily mean spicy the way that cayenne peppers or jalapeno peppers are spicy. Some other examples are things like ginger, garlic, onions, and even cinnamon are considered acrid in flavor. So it's that kind of spiciness. And then since acrid herbs are dispersing and drying, we'll want to use caution in cases of deficiency. Basically, if a person is already low on qi, we don't want to disperse what little qi they have left. And finally, we have salty. The salty flavor softens hardness and purges excess. So salty herbs can be used to treat hard nodules like goiter and scrofula. And salty herbs can purge accumulations or induce moist precipitation. These are just fancy ways of saying that they have a strong laxative effect. Think of like epsom salt, which is commonly used as a laxative. And as a side note, we're going to see that most of our medicinal substances that come from animal parts are going to be marked salty in flavor as well. So things like cicada skins, gecko tails, or deer antler are going to be marked salty in flavor. So those are the five tastes or the five flavors. And again, understanding these flavors allows us to make some connection between the taste of an herb and its therapeutic action. And then something that happens pretty often in Chinese medicine, whenever we have five of something, we tend to match it up with the five elements or the five phases. So each one of the five flavors corresponds to one of the five phases. And that's why we call it a five phase correspondence. So the sour flavor corresponds to the bitter flavor corresponds to fire, the sweet flavor corresponds to earth, the acrid flavor corresponds to metal, and the salty flavor corresponds to water. But what's made more interesting here is through these five phase correspondences, we can say that each taste is associated with an organ or channel. So the sour flavor enters a liver, the bitter flavor enters the heart, the sweet flavor enters the spleen, the acrid flavor enters the lung, and the salty flavor enters the kidney. So for example, herbs that are salty in flavor or have been prepared with salt tend to enter the kidney and treat kidney related disorders. Now I'm not sure that there's actually a good way to explain or remember these correspondences, but maybe we can try to make something up. So the sour flavor stops leakage and holds things in, and that's similar to the liver's function of storage. The bitter flavor clears heat and drains fire, and so it corresponds to fire. Or you can think about fire drying things out, and that's related to the bitter flavor's function of drying dampness. The sweet flavor tonifies, just like the spleen is our source of postnatal chi, and it tonifies the entire body through nutrition and proper digestion. The acrid flavor moves and disperses, just like when you do rhythmic breathing during qigong, you're using your lungs to move and circulate chi. Or you can think that the acrid flavor releases the exterior, and the lung governs the exterior and the opening and closing of the pores. And the salty flavor is associated with water because salt attracts water. If you eat a lot of salt, you'll get bloated because you're retaining water. Also, if you've ever eaten kidneys, like pork kidneys, you might know that they're salty in flavor because that's how the kidneys regulate water in the body, is through sodium gradients. So kidneys are literally salty. So maybe that's helpful, or maybe it isn't. Some of them are kind of a stretch. But the other thing we should look at is, besides the five flavors, we also have additional properties that help determine the actions of an herb. So besides sour, bitter, sweet, acrid, and salty, we can also say that herbs can be bland, aromatic, or astringent. So even though we call it the five flavors, they're really like seven or eight five flavors. So bland is more like a lack of flavor, but the bland flavor has the action of promoting urination and draining dampness. We usually use bland herbs for edema and water retention, or for urination problems like UTI. So we need to keep this straight. Bitter herbs dry dampness, meaning the dampness dries up and just disappears, but bland herbs drain dampness, meaning we're promoting urination to drain dampness out of the body. So don't get these two confused. And then aromatic isn't really a taste, it's more like a property. Aromatic herbs have a strong smell. They have a And this aromatic property has the action of opening and awakening. Aromatic herbs can open the sensory orifices, like the eyes, nose, and ears. Think about like Vic's Vapor Rub. The strong smell opens up your face. Aromatic herbs also open the heart orifices to revive the Shen, or awaken the spirit. And aromatic herbs also awaken the spleen. So think about like smelling salts. If a Similarly, aromatic herbs wake up the spleen so that it can perform its function of transforming dampness. That's why we might also say that aromatic herbs transform dampness. Astringent is another one that's not really a taste, it's more like a property. It's pretty much the same thing as sour, we just use it for herbs that have the ability to stop leakage, but aren't necessarily sour in flavor when you put them in your mouth. So there we have the seven, or eight, five flavors. Next, we can talk about entering channels, or the idea that herbs enter specific channels in order to have a therapeutic effect. So this is maybe a little bit weird, because the idea of entering channels kind of evolved over time in order to bridge the gap between acupuncture and herbs. So entering channels weren't really mentioned in the original Shen Nong Ben Cao Jing. They were first alluded to in the Song dynasty, but it wasn't until the Jin Yuan dynasty that they got explicitly mentioned. So part of what this means is there isn't always complete agreement between sources about which herbs enter which channels. So if you're looking at two different books and you have two different entering channels for the same herb, that's kind of normal. Or if you're looking at an herb and you don't understand why this herb enters these channels, or why this herb doesn't enter these channels, that's also kind of normal. But for us, I would say that entering channels are just another way of characterizing and understanding the functions of an herb. So if an herb stops cough, it probably enters a lung channel. If an herb calms the Shen, it probably enters the heart channel. If an herb brightens the eyes, it probably enters the liver channel, because the liver governs the eyes. If an herb strengthens the tendons and bones, it probably enters the liver and kidney channels, because the liver governs the tendons and the kidneys govern the bones. Things like that. So when we're going through the individual herbs, we want to try to make these connections when we can. But really, if you come across an herb and you don't understand why it enters a certain channel, I'd say don't worry about it too much. There may be a reason, but it might be a really weird and convoluted one. So for now, I would say just don't think too hard. If that all sounded really weird and confusing, let's look at an example. This is buo he, which is mint leaf. So here we see that buo he is the Chinese name, and menthi haplocalcus herba is the Latin pharmaceutical name. In terms of qi, or temperature, buo he is cool in temperature. So we know that it's used to treat warm conditions. Buo he is acrid in flavor. Remember the acrid flavor moves and disperses. So buo he disperses wind heat from the superficial levels of the body, and it also moves liver qi. Buo he is also aromatic. This refers to its ability to open orifices, opening up the eyes, head, and throat. If you're making mint tea, you can stick your face over it, and the fragrance of the steam will open up your eyes and nose. As far as entering channels go, buo he enters the lung and liver channels. It enters the lung channel because it releases the exterior and benefits the skin, and those are governed by the lung. It enters the liver channel because it moves liver qi and brightens the eyes, and the eyes are governed by the liver. So when we're going through the individual herbs, don't think of these properties as extra pieces of information that you have to memorize. Instead, try to understand an herb's functions in terms of its temperature, taste, and entering channels. Then the last thing we can talk is direction. Herbs can have a direction of action. They can move upward, downward, inward, outward, or go to a specific area of the body. For example, flowers tend to have a light ascending nature, so this upward direction makes them good for treating symptoms in the head and face. Roots and heavy minerals tend to have a downward direction, so they can move downward and anchor ascendant yang. Some of the diseases we treat have a direction associated with them. So for example, cough, nausea, and vomiting, we might say that the qi is rebelling upward, so we treat these conditions using herbs with a downward direction. Diarrhea or rectal prolapse could be qi sinking, so we counter that by using lifting herbs. If a pathogen is on the exterior trying to invade and work its way inward, we can use herbs with an outward direction to push the pathogen out. If fluids are leaking out, like in the case of spontaneous sweating, we can use herbs with an inward direction to hold things in. Then we have certain herbs that can guide the therapeutic effect of a formula to a specific part of the body. For example, qiang hu guides herbs to the upper body, while du hu guides herbs to the lower body. Jie geng can guide herbs to the chest. So this idea of an herb's direction can be kind of weird because it's not always explicitly stated. So if you open your textbook, you'll probably see sections for taste, temperature, and entering channel, but you won't necessarily see a section for the direction of an herb. For that, you might have to go looking through the commentary. So the directional property of an herb is more pronounced in some herbs than in other herbs, but it's still something we can keep in mind during a treatment. So those are the basic properties of herbs, and again, the reason we need to know this is because this is how we use Chinese herbs to treat patients. One of the mistakes I see beginning students make is they ask questions like, what's a good herb for insomnia? What's a good herb for diabetes? What's a good herb for when I get sick? And those are just the wrong questions to ask, because remember, in Chinese medicine, we're not treating symptoms, we're treating patterns of disharmony. So the way it works is, a patient comes in with a chief complaint, we ask them a bunch of questions about that chief complaint in order to come up with a diagnosis. That diagnosis informs our treatment principle, and then we prescribe herbs that line up with that treatment principle. For example, let's say you have a patient with a chief complaint of insomnia. After looking at the other signs and symptoms, you might come up with a pattern diagnosis of liver chi stagnation transforming into fire. So your treatment principle would be, drain fire and move liver chi. Since this is a warm condition, we'll probably want to use herbs that are cool in temperature. We'll probably use bitter herbs, since the bitter taste drains fire. And we'll probably combine that with acrid herbs, since the acrid flavor moves and disperses, and that'll take care of the underlying chi stagnation. And we'll use herbs that enter the liver channel. So that's how we would treat insomnia in this particular patient. But say we have another patient coming in with insomnia, but this time the other signs and symptoms are different. Here, based on these symptoms, we might diagnose spleen chi deficiency with heart blood deficiency. So our treatment principle would be, tonify spleen chi and tonify heart blood. So here, we'll probably use herbs that are warm in temperature and sweet in flavor, because the sweet flavor tonifies. And this time, we'll use herbs that enter the spleen and heart channels instead. So even though both of these people have insomnia, the way we treat them and the herbs we use are going to be very different, depending on the pattern diagnosis. So that's it for today. I hope this was helpful. If we haven't met, my name is Nicholas. I make videos about acupuncture and Chinese herbs. So if you're a student and you'd like to see more videos like this, consider subscribing below and checking out some of the other videos on this channel. But I hope you enjoyed this, because that's all for today. Thanks, and see you next time.