Yin and Yang of Chinese Herbs

I mentioned about using cooling tea to balance the heat in my body in previous article. So, what exactly is this cold or heat thingy about?

Yin and Yang of Chinese Medicine Diagnosis leads to Discovery of Yin and Yang of Chinese Herbs

Chinese Medicine was development based on the observation of the relationship between human body with the environment, and patterns of signs and symptoms instead of one specific identifiable disease. There was no advanced technology then, Traditional Chinese Medicine (TCM) doctors in the ancient times based their diagnosis on the symptoms expressed by the patient or signs observed by the physician. They noticed certain symptoms usually may accompanied with some other symptoms, so they grouped those symptoms together and gave a general name that represent a particular pattern. For example, common symptoms for Heat Pattern includes feverish sensation, dry mouth or throat, smelly stools, darker colour of urine, irritability, yellow tongue coating etc. These symptoms may not present all at once.

8 Guiding Principles for TCM Diagnosis  

Ancient TCM doctors slowly developed a concept called 8 Guiding Principles for diagnosis. These 8 Guiding Principles are interior or exterior, heat or cold, deficiency or excess, Yin or Yang. TCM doctors would look at all the signs and symptoms, then determine if it is a cold or heat pattern, if symptoms are mostly internal or external, are there any deficiency or excess in the body, are they generally belong to Yin or Yang properties. This is a very general way to look at illness.
Please bear in mind though, the above is only one of the many diagnosis methods for TCM doctors. I use this as an example simply because it is easiest to understand.

It is exactly because the diagnosis is very general , the goal of TCM treatment is to relieve the overall symptoms and general wellbeing. Therefore, as long as the patient feels their overall symptoms are generally improved, it is considered a good treatment. In the ancient times, there were no medicine that work at molecular level (eg antibiotics, antihypertensive etc), they could only make full use of what’s in the environment, like plants, animal parts or mineral. With no advanced technology or clinical trials, medicinal functions of herbs were discovered with many trials and errors, and how TCM categorised their herbs also based on quite general properties — Yin or Yang, basically.

This week, I am going to briefly discuss 2 main properties of herbs — their natures and flavours. There are other properties that I am not going to cover here because these two properties are enough for day-to-day use. I will write about the toxicity of Chinese herbs other time. Armed with the understanding of these properties, it would help us to create simple recipes for day-to-day use.

Four Natures (四气/四性)

Cold Pattern is treated with Hot herbs, and Heat Pattern is treated with Cold Herbs 疗寒以热药,疗热以寒药–Shen Nong’s Classic of Herbalism (神农本草经)

In ancient times, if someone has fever, after many trials, TCM doctor noticed a particular herb or formula could help to relieve the symptom. Since fever is considered a Yang symptom, then this herb must be a ‘cold’ herb, because it could ‘counteract’ the heat symptom. Someone may complain about feeling cold all the times, herbalist discovered that some herbs could help to warm up the body after ingesting them. Then these herbs must have warming property. Slowly, after hundreds and thousands of years of accumulated knowledge and experience, certain properties of Chinese herbs slowly emerge.

According to an ancient herbal medicine book compiled around Han Dynasty (202-220BC), Divine Farmer’s Classic of Materia Medica or Shen Nong’s Classic of Herbalism (神农本草经), herbs are already classfiied to into Four Natures and Five Flavours (see below).

The Four Natures are :

Nature Functions Associated Therapeutic Uses
Yang Hot Warm (the Yang in) the body, disperse coldness, unblocking the meridians Often used to treat Yin and Cold Patterns
Yin Cool Clear Heat in the body, cooling Often used to treat Yang and Heat Patterns

Hot is warmer than warm, cold is colder than cool. It is just the different degrees of warmth or coldness. Gaining more experience with herbs over time, and for more precise clinical use, some TCM doctors subdivided herbs to ‘very cold 大寒’, ‘very warm 大热’, ‘slightly cold 微寒’, or ‘slightly warm微热’. There is another nature is ‘Neutral’, for herbs that don’t have very obvious cold or warm nature.

Five Flavours (五味)

Chinese Herbs have 5 major flavours – sweet, salty, bitter, sour and spicy. Each flavour has its own associated therapeutic functions. Although there are more 5 flavours (like bland etc), these are the basic five we often referred to in Chinese herbs.

Some of these flavours can be easily identified by tasting, for example, ginger is spicy, mume fruit (chinese plum 乌梅) is sour, Chinese wolfberry (Goji berries 枸杞子) is sweet. However, some are extrapolated by known medicinal functions. For example, Kudzu root (葛根) doesn’t taste spicy, but because it has the ‘dispersing’ function in the body, it is considered it has a spicy flavour. Therefore, flavour profiles of Chinese herbs have dual significance : one being to represent their actual flavours, one is to give clues on their associated therapeutic actions.

Associated therapeutic Uses
Sweet 甘
Nourish and moisten the body, relieve pain and spasms, harmonise the actions of other herbs in a formula
Often used to treat general weakness, painful conditions, dryness. Some sweet herbs are used to neutralise toxic or side effects of other herbs or food.
Spicy 辛
Promote distribution and dispersion, enhance circulations of Qi and blood
Often used to treat at the symptoms that occurs at the more superficial level of the body or symptoms caused by external factors. One of the examples is mild viral or bacterial infections.
Often used for symptoms caused by sluggishness of Qi and Blood movement.
Bitter 苦
Clear heat, dry dampness, promote bowel movements, ensure the Qi flows in the body smoothly, reinforce Yin in the body
often used to treat condition with fever, heat signs, cough, constipation, nausea and vomiting etc
Salty 咸
dissipate accumulations, soften hardness and purgation
Often used to treat constipation, abnormal growth and accumulations.
Sour 酸
astringent and consolidate
Often used to treat conditions with abnormal sweating, cough, diarrhea, emission, incontinence and heavy menses etc

Wisdom and Art of formulating a Chinese Herbal Formula/Recipe 

Divine Farmer’s Classic of Materia Medica or Shen Nong’s Classic of Herbalism (神农本草经)So, you might think, seriously? Chinese Herbal Medicine is as simple as, if you have Cold Pattern, simply take some warming herbs then you will be ‘cured’? Yes or no. If the symptom is very mild and only temporary, probably yes. Otherwise, no.

The above are only half of the properties, the other half I haven’t covered here. Yet, just with the above, you have an endless combination of property profiles. For example, warm herbs that are sweet compared to warm herbs that are bitter, have totally different clinical applications. Moreover, when you put more than two herbs together, these herbs will interact with each other to produce different functions. For example, some herbs have synergistic effects, some herbs not only have similar therapeutic actions but also can counteract side effect of the other herbs. However, there are certain herbs when added to the formula/recipe will reduce or eliminate the actions of the others, this is what we don’t want.

In addition to that, as herbalist, I would consider many other factors, eg

  • person’s general wellbeing,
  • digestive health,
  • season/weather at the time of taking the herbs
  • age
  • gender
  • past experiences with Chinese herbs
  • other health conditions
  • other medication
  • etc

For example, long term use of cold herbs may affect the general digestive health, so I may add a couple of warm herbs in the formula to protect the stomach. Therefore, it is not necessary, if someone has Heat Pattern, we simply put together a few cold herbs, then that would be good enough.

Let’s say, if the same person with the same condition comes to see me but during different seasons, I would select different herbs. If s/he comes to see me during winter time, I may choose warmer herbs; if s/he comes during summer, I may choose cooler herbs.

Now, let’s combine the season/weather and digestive factors for this person. Based on my understanding of the person’s response to different season or weather, different herbs may be added to prevent those reactions to season/weather too. For example, if the weather forecast is heavy rain for the next few days, and this person always complaint heavy sensation and feeling very tired during rainy weather. In TCM, this is considered dampness in the environment causing dampness in the body. I shall then add one or two bitter herbs to dry the dampness. On top of that, add one or two bland or slightly sweet but warm herbs that can strengthen the digestive symptom because TCM believe if your digestive system is strong, it can help to clear the dampness in the body.

The above are only a few examples of the many things that going through a Chinese Herbalist’s head when s/he formulate a prescription.

Therefore, the recipes I collected or created in this blog, I may specifically tell you, which season/weather or under what circumstances is best to use, when not to take and precautions if there is any. The whole idea is to ensure whoever is taking the herbs will experience an overall improvement of symptoms.  It may not necessary be ‘curing’ the disease or relieving all the symptoms immediately, the good thing is the person will feel a sense of general wellbeing. For the purpose of this blog, it is NOT to cure anything, it is only for general wellbeing.

I shall stop here for this week. Some might find this topic is quite dry, hope that I haven’t bored you yet ! Wish you have enjoyed learning some basic properties of Chinese Herbs. So, next week we can start to learn Chinese herbs !


References :

  1.  Zhu Guo Fu (edited & compiled), Chinese Materia Medica, Qing Hua University Publisher, 2012 (朱国福主编 , 中药学 , 清华大学出版社,2012)

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