Recently, there has been an increasing number of patients testing positive for COVID-19. The number of people hoarding medicine, seeking medical advice, and taking medications indiscriminately is also on the rise. Various prevention and treatment suggestions are flourishing, but at the same time, it can feel overwhelming, akin to being dazzled by a myriad of flowers.
In Traditional Chinese Medicine (TCM), the principle is simple: the way is defined by yin and yang. Amidst the complexities, we need to return to the source of TCM treatment for exogenous diseases— the Treatise on Cold Damage (Shang Han Lun). The Treatise on Cold Damage is a clinical classic in TCM, serving as a guideline and gold standard for diagnosing and treating exogenous diseases. Regardless of the various interpretations and understandings of exogenous diseases throughout history and across cultures, the differential diagnosis methods and theoretical basis can be found in the six-channel differentiation of the Treatise on Cold Damage.
Below, I have created a simple differential diagnosis chart summarizing several main syndromes of exogenous diseases from the Treatise on Cold Damage. Readers can identify their syndrome based on their symptoms, which will clarify the general direction for treatment. I have listed representative formulas from the Treatise on Cold Damage in the chart. Unfortunately, there are currently no manufacturers in mainland China producing high-quality, standardized granules of these classical formulas. It is regrettable that the classical formulas from the Treatise on Cold Damage have been taken to Japan, where they are produced as high-quality granules and sold internationally. It is truly perplexing that there are no specialized manufacturers in mainland China producing series of classical granules, making it difficult to find the listed classical formulas such as Ma Huang Tang (Ephedra Decoction), Gui Zhi Tang (Cinnamon Twig Decoction), and Ma Huang Fu Zi Xi Xin Tang (Ephedra, Aconite, and Asarum Decoction) in the market. Readers have no choice but to go to pharmacies to get their prescriptions filled. Consequently, I can only use some modern formulas as substitutes. Of course, modern formulas cannot completely replace classical formulas; they can only maintain a general consistency in terms of the cold-heat direction of the prescriptions.
In the chart, the blue sections represent cold syndromes, while the red sections represent heat syndromes, corresponding to what later physicians referred to as “wind-cold/cold-type exogenous disease” and “wind-heat/heat-type exogenous disease.” Please consider this chart in conjunction with my previous article on the prevention and treatment of Omicron infection (pure TCM version).
Modern Interpretation
Sun Disease (Tai Yang Disease) (Ma Huang Tang: Ma Huang (Ephedra), Gui Zhi (Cinnamon Twig), Gan Cao (Licorice), Xing Ren (Apricot Kernel))
Chills: The body surface is affected by cold, leading to closed pores, constricted blood vessels, and poor microcirculation. The skin temperature receptors transmit cold signals to the brain. However, the overall energy of the patient is sufficient to mobilize a large amount of qi and blood to the skin surface to combat the “cold evil,” attempting to break through the microcirculation barrier, but the pores remain closed, resulting in a standoff between the righteous and the evil. Consequently, pressure leads to body pain; inability to dissipate heat results in fever. Treatment: Use Ma Huang to open the pores, induce sweating, and dissipate heat. Ma Huang is pungent and dispersing, warm in nature, and excels at opening the pores and inducing sweating, making it a powerful warming and dispersing agent. Modern pharmacological analysis has found that Ma Huang has a stimulating effect on the heart, promoting qi and blood to surge towards the skin surface. If Ma Huang is not available, any method that can warm the skin, open the pores, and enhance peripheral microcirculation can be used (see the chart above).
Representative passages from the Treatise on Cold Damage:
1. In Tai Yang disease, the pulse is floating, with stiffness and pain in the head and neck, and aversion to cold.
3. In Tai Yang disease, whether there is fever or not, there must be aversion to cold, body pain, nausea, and a pulse that is tight in both yin and yang, which is called cold damage.
Tai Yang Wind Stroke (Gui Zhi Tang: Gui Zhi (Cinnamon Twig), Sheng Jiang (Fresh Ginger), Zhi Gan Cao (Honey-Fried Licorice), Da Zao (Jujube), Shao Yao (Peony))
Aversion to wind: The patient may initially present with fever and aversion to cold as in Tai Yang cold damage, but then the body’s self-healing system activates, or the physician administers treatment, leading to opened pores and sweating. However, if sweating is not smooth, the cold evil is not completely eliminated, and the fever does not fully subside, it can lead to dysfunction of the autonomic nervous system that regulates skin circulation and sweating. Thus, the body becomes more prone to sweating, fluid loss occurs, and there is insufficient qi and blood at the skin surface, resulting in aversion to wind. However, the patient’s overall energy is not deficient; it is merely the body fluids that are somewhat depleted. Treatment: Supplement body fluids, mobilize qi and blood to compensate for the deficiency in peripheral circulation, and restore the regulatory function of the autonomic nervous system (in TCM, this is referred to as “harmonizing ying and wei”). Gui Zhi + Sheng Jiang + Da Zao + Zhi Gan Cao: pungent and sweet dispersing for yang; Shao Yao + Zhi Gan Cao + Da Zao: sour and sweet astringent for yin. One disperses and one astringes, achieving the effect of harmonizing ying and wei. Zhi Gan Cao and Da Zao nourish the body’s fluids. Gui Zhi Tang is indeed the ancestor of all formulas, deeply embodying the mystery of “the way is defined by yin and yang.”
Representative passages from the Treatise on Cold Damage:
12. In Tai Yang wind stroke, yang is floating and yin is weak. The floating yang indicates heat is self-generated; the weak yin indicates sweating occurs spontaneously. If there is aversion to cold, aversion to wind, fever, nasal congestion, and dry vomiting, Gui Zhi Tang is the main treatment.
13. In Tai Yang disease, headache, fever, sweating, aversion to wind, Gui Zhi Tang is the main treatment.
Shaoyin Cold Damage (Ma Huang Fu Zi Xi Xin Tang: Ma Huang (Ephedra), Xi Xin (Asarum), Pao Fu Zi (Processed Aconite))
Shaoyin cold damage is very similar to Tai Yang cold damage, with the main difference being in the pulse. Tai Yang cold damage presents with a floating tight pulse, while Shaoyin cold damage presents with a fine pulse. The pulse is a primary indicator for assessing yin and yang. In simple terms, patients with Tai Yang cold damage have sufficient overall energy to mobilize qi and blood to the skin surface to combat the cold evil, while patients with Shaoyin cold damage have insufficient energy and cannot mobilize qi and blood to the skin surface to fight the cold evil. When qi and blood energy is insufficient, the body’s instinct is to prioritize energy supply to vital organs, such as the internal organs, and cannot attend to the skin surface. It is like a country with insufficient military strength that cannot defend its borders against invading enemies but must concentrate its forces to protect its interior. Waiting for strength to build up before counterattacking. At this time, the skin surface is occupied by cold evil, blood vessels constrict, and microcirculation in the limbs is impaired, leading to cold extremities. Treatment: Supplement energy to mobilize qi and blood to the skin surface and open peripheral blood circulation. This can be done in two steps: first supplement energy, then open peripheral circulation. Alternatively, it can be done in one step, supplementing energy and opening microcirculation simultaneously. Ma Huang Fu Zi Xi Xin Tang is a formula that achieves this in one step. The Fu Zi in this formula is an energy-boosting herb, a very warming herb that can spread warmth to the limbs and body. Xi Xin is also a warming herb that facilitates the transport of Fu Zi to the skin surface, while Ma Huang opens the pores.Ma Huang induces sweating and releases the exterior, Fu Zi warms the meridians and assists yang, Xi Xin penetrates the exterior and interior.
Representative passages from the Treatise on Cold Damage:
281 In Shaoyin disease, the pulse is fine, and the patient only desires to sleep.
301 In Shaoyin disease, if the patient initially has fever and a submerged pulse, Ma Huang Fu Zi Xi Xin Tang is the main treatment.
Shaoyin Wind Stroke (Gui Zhi Jia Fu Zi Tang: Gui Zhi (Cinnamon Twig), Sheng Jiang (Fresh Ginger), Zhi Gan Cao (Honey-Fried Licorice), Da Zao (Jujube), Shao Yao (Peony), Pao Fu Zi (Processed Aconite))
Similarly, Shaoyin wind stroke is similar to Tai Yang wind stroke, but the main difference is also in the pulse and energy levels. Therefore, the treatment is Gui Zhi Tang plus Fu Zi.
Representative passages from the Treatise on Cold Damage:
20 In Tai Yang disease, if sweating occurs and does not stop, and the person has aversion to wind, difficulty urinating, and cold extremities that are difficult to bend, Gui Zhi Jia Fu Zi Tang is the main treatment.
Warm Diseases and Wind-Warmth
These correspond to the exterior syndromes of Tai Yang cold damage and Tai Yang wind stroke. The main difference is that the body feels hot rather than cold. This is because the body’s energy is not deficient; when pathogens invade, metabolism accelerates, and immune responses are heightened, leading to increased body heat. Warm diseases are characterized by a hot body but no sweating, indicating that heat cannot be dissipated. This may be due to fluid loss, resulting in no sweat, or it may be due to dysfunction of the autonomic nervous system’s temperature regulation. Wind-warmth is characterized by a hot body with sweating, but heat dissipation is not smooth, and the body continues to generate heat. Treatment principles: release the exterior and dissipate heat + clear interior heat. When the Treatise on Cold Damage discusses warm diseases and wind-warmth, it does not provide specific formulas, leading later physicians to believe that the Treatise on Cold Damage lacks formulas for treating warm diseases. During the Ming and Qing dynasties, the warm disease school emerged, creating effective formulas such as Yin Qiao San and Sang Ju Yin. In fact, the Treatise on Cold Damage does have formulas for treating warm diseases; Ma Xing Shi Gan Tang, Bai Hu Tang, and Ren Shen Bai Hu Tang can all treat warm diseases. They are categorized under the combined diseases of Tai Yang and Yang Ming, as well as Yang Ming diseases. In Ma Xing Shi Gan Tang, Ma Huang and Xing Ren can disperse the lungs and release the exterior to induce sweating, while Shi Gao can clear interior heat, and Zhi Gan Cao can nourish body fluids. Bai Hu Tang contains Shi Gao, Zhi Mu, Geng Mi, and Zhi Gan Cao, which can both clear heat and nourish body fluids. If body fluids are lost too much, Ren Shen can be added to Bai Hu Tang. These three formulas can be used alone or in combination to treat warm diseases and wind-warmth.
(Treatise on Cold Damage) Passages:
Ma Xing Shi Gan Tang:
63 After sweating, do not continue with Gui Zhi Tang. If sweating occurs and there is wheezing without high fever, Ma Huang Xing Ren Gan Cao Shi Gao Tang can be used.
Ma Huang Xing Ren Gan Cao Shi Gao Tang: Ma Huang (Ephedra), Xing Ren (Apricot Kernel), Zhi Gan Cao (Honey-Fried Licorice), Shi Gao (Gypsum).
Bai Hu Tang:
219 In the case of three yang combined diseases, with abdominal fullness and heaviness, difficulty turning over, numbness of the mouth and face, delirium, urinary incontinence, if sweating leads to delirium, and purging leads to sweating on the forehead, with cold extremities, Bai Hu Tang is the main treatment.
350 In cold damage, if the pulse is slippery and there is cold extremities, there is heat in the interior, Bai Hu Tang is the main treatment.
Bai Hu Tang: Zhi Mu, Shi Gao, Zhi Gan Cao, Geng Mi.
Bai Hu Jia Ren Shen Tang:
26 If after taking Gui Zhi Tang, there is profuse sweating and great thirst that does not resolve, with a large pulse, Bai Hu Jia Ren Shen Tang is the main treatment.
168 In cold damage, if there is vomiting or diarrhea for seven or eight days without resolution, with heat accumulation in the interior, heat in both the exterior and interior, with intermittent aversion to wind and great thirst, with a dry and irritated tongue, desiring to drink several liters of water, Bai Hu Jia Ren Shen Tang is the main treatment.
169 In cold damage, if there is no high fever, dry mouth and thirst, irritability, and slight aversion to cold, Bai Hu Jia Ren Shen Tang is the main treatment.
170 In cold damage, if the pulse is floating, with fever and no sweating, and the exterior is unresolved, Bai Hu Jia Ren Shen Tang is the main treatment.
222 If there is thirst and a desire to drink water, with dry mouth and tongue, Bai Hu Jia Ren Shen Tang is the main treatment.
Bai Hu Jia Ren Shen Tang: Zhi Mu, Shi Gao, Zhi Gan Cao, Geng Mi, Ren Shen.
Shaoyang Wind Stroke (Xiao Chai Hu Tang: Chai Hu (Bupleurum), Huang Qin (Scutellaria), Ren Shen (Ginseng), Zhi Gan Cao (Honey-Fried Licorice), Da Zao (Jujube), Sheng Jiang (Fresh Ginger), Ban Xia (Pinellia))
The Shaoyang syndrome occurs when the body is infected by pathogens, and due to spleen and stomach deficiency, the energy intake is insufficient, and the qi and blood energy is inadequate to expel the evil externally, resulting in a standoff between the righteous and the evil within the body, or what is called half-exterior half-interior, primarily in the chest and hypochondriac regions, leading to heat accumulation and irritability in the chest and hypochondrium. Additionally, when the body’s qi and blood energy slightly increases, it attempts to surge outward to induce sweating and release the exterior, presenting as fever; when qi and blood energy decreases, it retreats to the interior, leading to a deficiency of qi and blood at the skin surface, resulting in aversion to cold. This is the back-and-forth of cold and heat. Because the qi and blood of the spleen and stomach are already deficient, combined with the external pathogen consuming a large amount of qi and blood, the spleen and stomach become even more deficient, leading to a lack of appetite and a tendency to vomit after eating. Treatment: a combination of purging and tonifying, supplementing the qi and blood of the spleen and stomach, and clearing the heat and obstruction in the chest and hypochondrium. Chai Hu: unblocks the obstruction in the chest and hypochondrium; Huang Qin: clears heat in the chest and hypochondrium; Ban Xia: directs water and phlegm downwards in the chest and hypochondrium; Ren Shen, Zhi Gan Cao, Da Zao, Sheng Jiang: these four herbs strengthen the spleen and stomach and nourish body fluids.
Representative passages from the Treatise on Cold Damage:
96 In cold damage for five or six days, if there is wind stroke, with alternating chills and fever, fullness and discomfort in the chest and hypochondrium, lack of desire to eat or drink, irritability, or discomfort in the chest without vomiting, or thirst, or abdominal pain, or hardness in the hypochondrium, or palpitations, with difficulty urinating, or no thirst, with slight fever, or cough, Xiao Chai Hu Tang is the main treatment.
97 If the blood is weak and qi is exhausted, the pores open, and the evil qi enters and clashes with the righteous qi, leading to a standoff in the hypochondrium. The struggle between the righteous and the evil leads to alternating chills and fever, with periods of rest, and lack of desire to eat. The pain must be relieved. If the evil is high, it causes pain below, leading to vomiting. (One theory states: if the zang-fu organs are in conflict, the disease must descend.) Pain in the hypochondrium, Xiao Chai Hu Tang is the main treatment. If after taking Xiao Chai Hu Tang, there is thirst, it belongs to Yang Ming, and should be treated accordingly.
Above, we have analyzed several common syndromes of exogenous diseases in the Treatise on Cold Damage: Tai Yang cold damage, Tai Yang wind stroke, Shaoyin cold damage, Shaoyin wind stroke, warm diseases, wind-warmth, and Shaoyang wind stroke. If everyone can understand and master these typical syndromes of exogenous diseases and apply them flexibly, they can differentiate and treat most exogenous diseases. However, viruses are ever-changing, and human constitution varies widely; exogenous diseases in actual clinical practice are also complex and variable. This article merely simplifies the complex, providing an outline, and is indeed a superficial discussion. If there are errors or inappropriate points, I welcome criticism and correction from readers, experts, and colleagues.
Today marks the 111th anniversary of the birth of Mr. Qian Xuesen. As a scientific leader, he worked hard to promote the modernization of TCM, serving as a banner and example for our generation. In this time of rampant viruses, I dedicate this article to commemorate Mr. Qian, hoping that TCM can achieve new successes in protecting the health and lives of the people, to comfort Mr. Qian’s spirit in heaven.
Note: I have not provided dosages because this article only offers suggestions and discusses theoretical principles, not intended for prescribing treatment. For specific prescriptions, please consult local professional TCM practitioners online.