Part 7: Properties of Traditional Chinese Medicine: Four Natures, Five Flavors, Ascending and Descending Properties, and Toxicity
III. Properties of Traditional Chinese Medicine
The fundamental function of medication in treating diseases is to eliminate pathogenic factors, restore the harmony of organ functions, and thereby correct the imbalance of Yin and Yang, restoring the body to a normal state. This is because various drugs possess certain characteristics and effects, namely, their specific properties. Medication treats diseases by using these properties to correct the imbalance of Yin and Yang manifested in the disease.
The diverse properties and effects of traditional Chinese medicine in treating diseases can be summarized in terms of four natures, five flavors, ascending and descending properties, and toxicity, collectively referred to as the properties of traditional Chinese medicine.
1. Four Qi
The four properties of medicines-cold, hot, warm, and cool-were anciently known as the "Four Qi." Medicines that can alleviate or eliminate heat symptoms are generally cold or cool in nature; medicines that can alleviate or eliminate cold symptoms are generally warm or hot in nature.
Warmth and heat, cold and coolness are two different categories of properties. Warmth and heat, cold and coolness share commonalities, but there are also differences in degree: warmth is less than heat, and coolness is less than cold. For some medicines, they are often further distinguished by terms such as very hot, very cold, slightly warm, and slightly cold.
In addition, there are some neutral medicines whose properties of cold and heat are not very pronounced, and their effects are relatively mild.
2. Five flavors
The five basic tastes-pungent, sweet, sour, bitter, and salty-were traditionally known as the "five flavors." However, medicinal substances actually possess more than five flavors; they also include bland and astringent tastes. Different medicinal flavors have different effects, and medicinal substances with the same flavor often have similar effects.
Pungent: It has the effects of dispersing, regulating qi and blood, and is used to treat superficial syndromes or syndromes of qi and blood stagnation.
Sweet: It has the effects of tonifying, harmonizing the middle and relieving spasms. It is used to treat deficiency syndromes, relieve stiffness and pain, and harmonize the properties of other medicines.
Sourness: It has astringent and consolidating effects and is used to treat symptoms such as night sweats and diarrhea.
Astringent: It has the effects of astringing and consolidating, and is used to treat symptoms such as night sweats, diarrhea, frequent urination, spermatorrhea, and bleeding.
Bitter: It has the effects of purging, descending, clearing, drying dampness, and strengthening yin. It is used to treat constipation due to heat accumulation, cough with shortness of breath, irritability due to excessive heat, dampness syndrome, and yin deficiency with fire excess.
Salty: It has the effects of softening and dispersing nodules and purging, and is used to treat scrofula, phlegm nodules, abdominal masses, constipation due to heat accumulation, and other symptoms.
Bland: It has the effects of draining dampness and promoting urination, and is used to treat edema, difficulty in urination, and other symptoms.
Each Chinese herb possesses both properties and flavor. If herbs have the same properties but different flavors, or vice versa, their effects will differ. Therefore, analyzing the efficacy of herbs requires considering both their properties and flavors.
Only by understanding all the properties of each Chinese herb and the differences in properties between herbs with the same properties can we accurately apply Chinese herbal medicine.
3. Rising, falling, floating, and sinking
Various diseases often exhibit downward (e.g., diarrhea, rectal prolapse), upward (e.g., cough, asthma, vomiting), inward (e.g., unresolved external symptoms, poor rash eruption), and outward (e.g., spontaneous sweating, night sweats) tendencies. Therefore, drugs that improve or eliminate these symptoms tend to have ascending, descending, floating, and sinking effects, respectively.
This property can correct bodily dysfunctions, restore them to normal, or guide the body to expel pathogens.
Ascending and descending, floating and sinking are all relative concepts. Ascending means rising, descending means falling, floating indicates dispersion, and sinking indicates purging. Generally, drugs with effects such as raising yang and releasing exterior pathogens, dispelling wind and cold, inducing vomiting, and opening orifices have ascending and floating properties; while drugs with effects such as purging, clearing heat, promoting diuresis and eliminating dampness, calming the mind and spirit, suppressing yang and extinguishing wind, eliminating stagnation, descending adverse flow of qi, astringing, relieving cough and asthma have sinking and descending properties.
The ascending, descending, floating, and sinking properties of drugs are related to the following factors: First, the nature and flavor of the drug. Drugs that can ascend and float mostly have pungent, sweet, warm, or hot properties, while drugs that can sink mostly have sour, bitter, salty, or astringent tastes and cold or cool properties. Second, the processing of the drug. Stir-frying with wine makes it ascending, stir-frying with ginger juice makes it disperse, stir-frying with vinegar makes it astringent, and stir-frying with salt water makes it descend. Third, the compatibility of the compound prescription. The ascending, descending, floating, and sinking properties of a drug may be constrained by the properties of most drugs in the compound prescription.
4. Toxicity
In ancient medical literature, "poison" was a general term for drugs. Each drug had its own specific properties, and these properties were referred to as "poison." However, in modern Chinese medicine books, the labels "highly toxic," "toxic," and "slightly toxic" under the properties of drugs indicate that the drugs have a certain degree of toxicity or side effects. Improper use can lead to poisoning, which must be taken seriously.
Understanding the toxicity, non-toxicity, high toxicity, and low toxicity of various drugs helps us comprehend the strength or mildness of their effects, allowing us to appropriately select drugs and determine dosages based on the patient's constitution, the severity of the illness, and other relevant factors. Furthermore, necessary processing, compatibility, and formulation steps can mitigate or eliminate harmful effects, ensuring medication safety.
IV. Application of Traditional Chinese Medicine
The application of traditional Chinese medicine includes aspects such as compatibility, formulation, contraindications, and dosage. Mastering this knowledge is crucial for maximizing efficacy and ensuring medication safety.
1. Compatibility
When the condition is relatively simple, a single targeted drug can achieve the desired effect; this was traditionally called "single-herb treatment," meaning treating the disease with a single herb. Such prescriptions are called "single-herb formulas." Single-herb formulas have the advantages of being highly effective and potent, meeting the requirements of being simple, convenient, inexpensive, and effective, making them easy to use and promote.
When the condition is complex, a single herb may not be sufficient to meet the treatment requirements of both distinguishing between primary and secondary symptoms and addressing all aspects of the condition. Therefore, it is necessary to use two or more herbs at the same time, which is called drug combination.
The combination of drugs can produce certain interactions, which can be broadly categorized into the following four aspects: ① Some drugs enhance efficacy due to synergistic effects, a phenomenon known in ancient times as "mutual reinforcement" or "mutual aid," which should be fully utilized when using medication; ② Some drugs may antagonize each other, canceling or weakening their original effects, a phenomenon known in ancient times as "mutual antagonism," which should be noted when using medication; ③ Some drugs can reduce or eliminate their original toxicity or side effects due to interactions, a phenomenon known in ancient times as "mutual antagonism" or "mutual killing," which must be considered when using toxic or potent drugs; ④ Some drugs that are harmless when used alone may produce toxic reactions or strong side effects due to interactions, a phenomenon known in ancient times as "mutual opposition," which is considered a contraindication to drug combination and should be avoided in principle.
The combined use of drugs is the main form of medication in Traditional Chinese Medicine (TCM). Drugs are combined according to certain rules and proportions to form appropriate dosage forms; this is called a prescription.
2. Formula
There are certain principles for composing prescriptions from drugs, namely, dividing them into principal drugs, auxiliary drugs, and adjuvant drugs.
(1) Main medicine: It plays a major therapeutic role in the prescription, targeting the main disease or main symptom.
(2) Auxiliary drugs: In the prescription, they assist the main drug, enhance the efficacy of the main drug, or treat concurrent symptoms.
(3) Adjuvant drugs: to restrain the toxicity and side effects of the main drug, assist in the treatment of secondary symptoms, guide the drug to the disease site, or be used as flavoring or excipients.
Therefore, the significance of combining drugs into prescriptions lies in leveraging their synergistic effects to adapt to the condition and enhance efficacy; at the same time, it can prevent the toxicity and side effects of certain drugs.
3. Taboos
Traditional Chinese medicine practitioners have discovered through long-term medical practice that some drugs cannot be used together, otherwise it will affect the efficacy of the drugs or even cause adverse reactions.
(1) Mutual Incompatibility: When two drugs are used together, they can restrain each other, reducing or canceling the original effects of the drugs. This is called mutual incompatibility. There are nineteen common types, commonly known as the "Nineteen Antagonisms". They are: sulfur is incompatible with sodium sulfate, mercury is incompatible with arsenic, wolfsbane is incompatible with litharge, croton is incompatible with morning glory seeds, clove is incompatible with turmeric, potassium nitrate is incompatible with sparganium rhizome, aconite and aconitum carmichaelii are incompatible with rhinoceros horn, ginseng is incompatible with trogopterus dung, and cinnamon is incompatible with red ochre.
(2) Incompatible: When two drugs are used together, adverse reactions or toxic effects may occur. This is called incompatibility. There are eighteen common incompatibilities, commonly known as the "Eighteen Incompatibilities". These are: Licorice is incompatible with Euphorbia pekinensis, Euphorbia kansui, Daphne genkwa, and Sargassum; Aconitum is incompatible with Fritillaria cirrhosa, Trichosanthes kirilowii, Pinellia ternata, Scutellaria baicalensis, and Bletilla striata; Veratrum nigrum is incompatible with Ginseng, Salvia miltiorrhiza, Adenophora stricta, Scrophularia ningpoensis, Sophora flavescens, Asarum heterotropoides, and Paeonia lactiflora.
4. Dosage
Dosage refers to the amount of medicine used. Unless otherwise specified, the dosages listed for each Chinese herb in this book refer to the daily adult dosage of the dried raw herb.
Generally speaking, most Chinese medicines are raw herbs, which are mild in nature and have a wide range of safe dosages. Therefore, their dosage is not as strict as that of chemical drugs. However, for certain potent or toxic drugs, the dosage must be strictly controlled to prevent accidents.
Dosage should be controlled from the following aspects: For drugs that are potent or toxic, the dosage should be small, starting with a small amount and gradually increasing according to the condition; once the condition improves, the dosage should be gradually reduced or discontinued to prevent poisoning or side effects.
Light or easily decocted herbs, such as flowers and leaves, should be used in smaller quantities; heavy or difficult-to-decoct herbs, such as minerals and shells, should be used in larger quantities. For the same herb, the dosage should be larger in decoctions than in pills or powders; the dosage should be larger for single herbs than in compound formulas; the dosage should be larger (1-2 times more) for fresh herbs than for dried herbs; and the dosage of the principal herb in a compound formula should be larger than that of the auxiliary herbs.
Those with serious illnesses, acute illnesses, or strong constitutions should take a higher dosage; those with mild illnesses, chronic illnesses, weak constitutions, or the elderly should take a lower dosage.