Climatic Characteristics of Hangzhou's Plum Rain Season and Their Impact on the Human Body
Hangzhou is situated in the Jiangnan water-town region. From June to July each year, under the influence of the quasi-stationary front along the middle and lower reaches of the Yangtze River, the city enters its annual plum rain season. During this period, relative humidity in the air remains above 80% for extended periods, with temperatures ranging between 25-32°C, creating a typical high-temperature, high-humidity environment. The classic TCM text Huangdi Neijing states: "When dampness prevails, loose stools occur." Dampness is a yin pathogen, characterized by heaviness, turbidity, and stickiness, and it readily damages yang qi.
From the perspective of the five-element theory in TCM, late summer belongs to the earth element, corresponding to the spleen and stomach among the five zang organs. The spleen governs transportation and transformation, and prefers dryness while disliking dampness. When external dampness is excessive, the spleen's transportation and transformation function is the first to be suppressed, leading to internal retention of water-dampness and impaired movement of qi. Common discomforts during the plum rain season include: heaviness and fatigue of the body, a sensation of head heaviness as if wrapped in cloth, chest tightness and epigastric stuffiness, poor appetite, sticky and unformed stools, thick and greasy tongue coating, and joint aching and distension. For those with a constitution predisposed to spleen deficiency with exuberant dampness or damp-heat constitution, the plum rain season is especially difficult to endure.
Nature and Pathogenic Characteristics of Dampness
TCM holds that dampness possesses the properties of heaviness and turbidity, stickiness and stagnation, and a tendency to descend. "Heaviness and turbidity" means that dampness as a pathogen often causes the head and body to feel heavy and the limbs to feel sore and lazy; "stickiness and stagnation" manifests as symptoms that linger and are difficult to resolve, with a prolonged course, such as sticky and unsatisfying bowel movements, a sticky or sweet taste in the mouth, and thick greasy tongue coating; "tendency to descend" refers to dampness easily damaging the lower part of the body, commonly causing lower limb edema and increased vaginal discharge. During the plum rain season, external dampness and internal dampness generated by insufficient spleen transportation and transformation mutually trigger each other, forming a combined internal-external pathogenic force.
In addition, dampness has another important characteristic—it readily obstructs the movement of qi. Dampness is a tangible yin pathogen, dense and sticky in nature, and most easily impedes the ascending, descending, exiting, and entering of qi movement in the body. The spleen and stomach reside in the middle jiao and serve as the pivot for the ascending and descending of qi throughout the body. After dampness encumbers the spleen, both the spleen's function of raising the clear and the stomach's function of lowering the turbid are simultaneously obstructed. If clear yang fails to ascend, the head and eyes lose nourishment, resulting in dizziness and drowsiness; if turbid yin fails to descend, there is epigastric and abdominal stuffiness and distension with loss of appetite. This state of qi movement congestion further aggravates the accumulation of dampness, forming a vicious cycle.
Regarding the spleen and stomach's function of transporting and transforming water-dampness, two acupoints in TCM meridian theory are closely related to wellness during the plum rain season. Zusanli, also known as Xialing or Sanli, is located on the anterolateral aspect of the lower leg, 3 cun below Dubi, one finger-breadth lateral to the anterior crest of the tibia. It belongs to the Foot Yangming Stomach Meridian and is the He-Sea point of the Stomach Meridian and the lower He-Sea point of the Stomach. The Lingshu states: "When pathogenic factors are in the spleen and stomach... all are regulated through Zusanli." This point is recognized in TCM as a key acupoint for regulating the spleen and stomach's transportation and transformation function. Yinlingquan, also known as Yinzhilingquan, is located on the medial aspect of the lower leg, in the depression between the lower border of the medial condyle of the tibia and the medial border of the tibia. It belongs to the Foot Taiyin Spleen Meridian and is the He-Sea point of the Spleen Meridian. The He-Sea point of the Spleen Meridian corresponds to the spleen's function of transporting and transforming water-dampness, and thus holds special significance in the theoretical framework of dampness encumbering the spleen.
Constitutional Susceptibility to Dampness During the Plum Rain Season
Why is it that some people remain perfectly well while others feel unwell all over despite living in the same plum rain environment? TCM holds that this is closely related to individual constitutional foundations. The spleen is the foundation of acquired constitution and governs the transportation and transformation of water-dampness. The strength or weakness of the spleen's transportation and transformation function determines the body's resistance to dampness. Those with a constitution of spleen deficiency have inherently weak transportation and transformation; upon encountering external dampness, internal and external factors combine and like attracts like. Those with insufficient yang qi lack the power to warm and transform water-dampness, making dampness more likely to transform toward cold. Those who indulge in rich, greasy, and sweet foods have long-standing stagnation in the spleen and stomach, and dampness tends to transform toward heat. Therefore, wellness care during the plum rain season is not a one-size-fits-all approach; it requires different emphases according to constitutional characteristics.
Analysis of Etiology and Pathogenesis
From the perspective of etiology, heavy dampness during the plum rain season is the external cause, while irregular diet, excessive consumption of cold and greasy foods, prolonged sitting with little movement, and emotional constraint are internal causes. External dampness invades the body surface, internal dampness arises from the spleen and stomach, and the two seek each other out. The disease location is primarily in the spleen and stomach. The spleen and stomach serve as the pivot for the ascending and descending of qi movement. When dampness encumbers the spleen, clear yang fails to ascend and turbid yin fails to descend, hence the sensation of head heaviness as if wrapped in cloth and epigastric and abdominal distension. In terms of disease nature, dampness is a yin pathogen that readily damages spleen yang and is sticky and difficult to resolve, often accompanied by cold, heat, or qi stagnation.
From the perspective of disease progression, if dampness lingering in the middle jiao is not promptly addressed, it may follow various transmission and transformation trends. First, due to prolonged depletion of spleen yang and failure to warm and nourish kidney yang, the disease may spread from the spleen to the kidney, producing signs of spleen-kidney yang deficiency such as soreness and weakness of the lower back and knees, lower limb edema, and aversion to cold with cold limbs. Second, dampness stagnating in the body for a long time may transform into heat, forming a pattern of damp-heat steaming, which may manifest as dry mouth, bitter taste, scanty dark urine, and skin eczema. Third, dampness encumbering and qi stagnating—if qi does not move, blood circulation becomes impeded, and over time phlegm and blood stasis may bind together, producing deeper pathological changes such as limb numbness and joint swelling and pain. It is evident that the dampness of the plum rain season, though seemingly ordinary, can involve rather complex pathological evolution if left unaddressed.
When dampness stagnates for a prolonged period, it often accumulates to form phlegm. In TCM meridian theory, Fenglong acupoint is closely related to phlegm-dampness pathogens. Fenglong, also known as Fenglong, is located on the anterolateral aspect of the lower leg, 8 cun above the tip of the external malleolus, 1 cun lateral to Tiaokou acupoint, two finger-breadths lateral to the anterior crest of the tibia. It belongs to the Foot Yangming Stomach Meridian and is the Luo-Connecting point of the Stomach Meridian. The Yulong Ge states: "For excessive phlegm, seek Fenglong." Luo-connecting points have the function of connecting the paired interior-exterior meridians. The Luo-connecting point of the Stomach Meridian connects with the Spleen Meridian, and therefore Fenglong acupoint is often mentioned in TCM theory regarding internal retention of dampness-turbidity and excessive phlegm-dampness.
Classic Interpretation: When Dampness Prevails, Loose Stools Occur
The meaning of this passage from the Huangdi Neijing is that when dampness is excessive, it causes dysfunction in the spleen and stomach's transportation and transformation, so that water-dampness cannot be properly distributed and excreted, instead mixing with the stool and descending, resulting in loose stools and diarrhea. In plain terms, the spleen is like a water pump; under normal conditions, it can transport water from the body upward to the lungs, which then distribute it throughout the body. When external dampness is too heavy or the spleen's function is weakened, this water pump "goes on strike," and water-dampness is directly discharged through the intestines, manifesting as diarrhea or unformed stools. In other words, the dampness of the plum rain season does not directly damage the intestines; rather, it first encumbers the pivot of the spleen's transportation and transformation, disrupting the orderly distribution of fluids. This also reminds us that the key to wellness during the plum rain season lies in protecting the spleen and stomach's transportation and transformation function.
Among the nineteen articles on pathogenesis in the Huangdi Neijing, there is further the statement: "All dampness, swelling, and fullness belong to the spleen." This further attributes the pathogenesis of all dampness-related disorders to the spleen. Failure of the spleen's transportation and transformation is the core link in the internal generation of dampness; external dampness is merely a triggering factor. From this perspective, wellness during the plum rain season should not involve panicking about external humidity, but rather focusing on fortifying one's own spleen transportation function. When the spleen is strong, dampness has nowhere to accumulate—just as fertile land allows standing water to naturally seep in and dissipate.
TCM Pattern Differentiation of Dampness-Prone Constitutions
In TCM clinical practice, constitutional imbalances related to dampness during the plum rain season are primarily divided into the following types. Only by clearly identifying the type can one understand the signals the body is sending and take corresponding measures.
1. Cold-Dampness Encumbering the Spleen Type
Main manifestations: aversion to cold and wind, cold limbs, cold and painful abdomen, loose stools, often accompanied by a bland taste in the mouth without thirst, and a preference for warm drinks. The sensation of head and body heaviness is particularly pronounced, with soreness and aching in the muscles all over, as if the body is wrapped in a wet cloth, most prominent upon waking in the morning. The tongue typically presents as pale and swollen with white slippery or white greasy coating, with the tongue surface so wet it appears about to drip. The pulse is typically soft and slow or deep and thin.
In terms of accompanying symptoms, these individuals often feel heaviness and coldness in the limbs and joints during the plum rain season, which worsens on rainy days and improves with warmth. Appetite is reduced, not due to food stagnation, but because of insufficient middle yang and impaired transportation and transformation. Women may experience clear, thin, and profuse vaginal discharge, while men may experience dampness and coldness of the scrotum.
The key differentiating point is the obvious "cold signs," such as cold hands and feet, worsening with cold exposure, and improvement with warmth. This is commonly seen in those with pre-existing yang qi insufficiency, those who prefer cold and raw foods, or those who have long resided in cold and damp environments. Regulation should follow the principles of warming the middle, dispersing cold, fortifying the spleen, and drying dampness. TCM theory holds that "when the sun shines brightly above, the dark clouds disperse on their own"—when the yang of the spleen and stomach is restored, cold-dampness pathogens resolve naturally.
2. Damp-Heat Accumulation Type
Main manifestations: heaviness and fatigue of the body, dry and bitter taste in the mouth, yellow and dark urine, sticky and burning unsatisfying bowel movements, or skin eczema and acne. Although there is body heaviness, it is accompanied by heat signs—sticky and uncomfortable sweating, sweat that is yellow or leaves yellow stains, and excessive oil secretion on the face and scalp. The tongue typically presents as red with yellow greasy coating, with red raised spots visible along the edges. The pulse is typically slippery and rapid.
In terms of accompanying symptoms, these individuals tend to be irritable and easily angered, with a sticky sweet or bitter taste in the mouth and heavy, turbid breath in the morning. The digestive system may show epigastric and abdominal stuffiness, distension, nausea, and acid regurgitation, yet paradoxically there is thirst with a preference for cold drinks. Urine is scanty and yellow, and there is a pronounced burning sensation at the anus during bowel movements, with a feeling of incomplete evacuation afterward.
The key differentiating point is the prominent "heat signs," such as thirst with preference for cold drinks, bitter taste in the mouth, and yellow urine. Damp-heat binding together is like oil mixed into flour—thoroughly combined and difficult to separate—hence the lingering symptoms. This is commonly seen in those who indulge in spicy and greasy foods and consume alcohol frequently. Regulation should follow the principles of clearing heat, draining dampness, fortifying the spleen, and harmonizing the stomach. However, clearing heat should not rely excessively on bitter-cold medicinals, lest they damage spleen and stomach yang qi. It is necessary to supplement dampness transformation with heat clearing, allowing dampness and heat to be resolved separately.
3. Spleen Deficiency with Exuberant Dampness Type
Main manifestations: sallow complexion, mental fatigue and lack of strength, poor appetite and abdominal distension, thin and loose stools, diarrhea after eating even small amounts of greasy food, often accompanied by shortness of breath and disinclination to speak, and limb edema. Eyelid puffiness is pronounced upon waking in the morning, with mild lower limb edema in the afternoon that pits on pressure and does not rebound. Drowsiness and lethargy after meals, with fatigue from even slight activity. The tongue typically presents as pale and swollen with teeth marks on the edges and white greasy coating. The pulse is typically thin and weak or soft and slow.
In terms of accompanying symptoms, these individuals experience reduced memory, difficulty concentrating, dull and heavy head and eyes, and sluggish thinking as if shrouded in fog. The voice is low and speech lacks strength. Due to prolonged spleen deficiency, qi and blood generation is insufficient, and signs of blood deficiency such as dizziness, palpitations, and scanty pale menstruation may also be observed.
This is a relatively common type, mostly seen in those with congenital spleen and stomach weakness, irregular diet, or excessive taxation and fatigue. The key differentiating point is the prominent "deficiency signs," namely fatigue and lack of strength appearing together with dampness encumbrance, with fatigue and weakness as the core and dampness encumbrance as the secondary manifestation. Regulation should follow the principles of fortifying the spleen, supplementing qi, draining dampness, and promoting diuresis. When the spleen is fortified, transportation and transformation are effective; when transportation and transformation are effective, water-dampness resolves on its own—this is the fundamental approach.
Key Differentiating Points Among the Three Types
Both cold-dampness encumbering the spleen and spleen deficiency with exuberant dampness present with aversion to cold and loose stools, but in cold-dampness, abdominal cold pain is pronounced and improves with warmth, with more severe coldness of the extremities; whereas in spleen deficiency, fatigue, poor appetite, and sallow complexion predominate, with relatively milder cold aversion, which is a deficiency-cold resulting from insufficient yang qi generation.
Damp-heat accumulation presents with thirst, bitter taste, yellow-dark urine, and yellow greasy tongue coating, forming a sharp contrast with the white coating seen in cold-dampness and spleen deficiency. In addition, in damp-heat, stools are sticky and burning, whereas in cold-dampness and spleen deficiency, stools are thin and watery without foul odor or with only a food odor—fishy and cold without a burning sensation.
If one can promptly identify one's own constitutional imbalance, it will be more helpful in selecting appropriate dietary and lifestyle care measures.
TCM Dietary Care Plan
Food is the foundation of life, and dietary care during the plum rain season is of paramount importance. TCM emphasizes the concept of "medicine and food sharing the same origin," and through daily dietary regulation, it is possible to help improve dampness-prone constitutions to a certain extent. The purpose of dietary care is not to eliminate pathogens, but to restore the spleen and stomach's autonomous transportation and transformation power. This requires sustained effort over time, not results achieved in a single day.
Basic Principles of Medicine-Food Homology
Many foods inherently possess regulatory effects—such as coix seed, poria, and Chinese yam—serving as both everyday ingredients and commonly used items in TCM. The principle lies in leveraging the nature, flavor, and meridian entry of foods to restore the spleen and stomach's transportation and transformation function, enabling water-dampness to be properly metabolized. TCM holds that each of the five zang organs has a flavor it favors; the spleen corresponds to the sweet flavor, and sweet enters the spleen. Therefore, most spleen-fortifying, dampness-transforming items carry a sweet and bland nature. Sweetness supplements the spleen, blandness drains dampness—the two working together to strengthen spleen qi while providing an outlet for water-dampness.
During the plum rain season, the diet should follow the general principles of being light, easy to digest, and spleen-fortifying and dampness-transforming, avoiding aggravation of the spleen and stomach's burden. Cooking methods should favor steaming, boiling, stewing, and braising, with less frying and grilling, to preserve the natural properties of ingredients.
Recommended Ingredients
- Spleen-fortifying and dampness-transforming category: Coix seed (Job's tears), white hyacinth bean, poria, Chinese yam, lotus seed, and Euryale seed. Among these, coix seed is a commonly used item for dispelling dampness and can be cooked as porridge or soup. White hyacinth bean is warm in nature and sweet in flavor, particularly effective at transforming dampness in the middle jiao; Chinese yam gently supplements the three zang organs of spleen, lung, and kidney, tonifying both qi and yin; poria blandly drains water without damaging healthy qi, being an excellent item that both supplements and drains.
- Aromatic dampness-transforming category: Agastache rugosa (huoxiang), Eupatorium fortunei (peilan), Amomum fruit (sharen), and dried tangerine peel (chenpi). These aromatic medicinal herbs have fragrant odors that can move qi and transform dampness, awakening the spleen and opening the appetite. Aromatic items are adept at reaching the middle jiao, capable of mobilizing the pivot, allowing spleen and stomach qi to ascend and descend in an orderly manner. Adding a small amount during cooking both enhances flavor and aids dampness transformation.
- Heat-clearing and dampness-draining category: Adzuki bean, mung bean, winter melon, and lotus leaf. Suitable for those with a constitution predominated by damp-heat. Adzuki bean is adept at descending and promoting the water passages; winter melon, both flesh and rind, can be used in meals, draining water without damaging yin; lotus leaf raises the clear and lowers the turbid, gently diffusing heat from the upper jiao.
- Middle-warming and cold-dispersing category: Fresh ginger, dried ginger, Sichuan pepper, and cinnamon. Suitable for those with a cold-dampness constitution to add in moderation during cooking. These pungent-warm items can warm and disperse cold from the middle jiao, helping restore spleen and stomach yang qi, but those with yin deficiency and internal heat should not consume them excessively.
Recommended Classic Dietary Recipes
Coix Seed and Adzuki Bean Porridge: Use coix seed and adzuki bean as the main ingredients, optionally adding a small amount of rock sugar for flavor, and cook until the porridge is done. This porridge helps drain water and seep out dampness, fortify the spleen, and reduce swelling, making it a classic dietary recipe for the plum rain season. Coix seed excels at eliminating dampness from the spleen and stomach, while adzuki bean excels at draining water-dampness from the lower jiao. Combined, the two resolve dampness from both above and below, allowing water-dampness to exit through urination. Note that excessive rice should not be added, as it may diminish the dampness-dispelling effect.
Chinese Yam and Poria Pork Rib Soup: Take Chinese yam, poria, and pork ribs and stew together, adding a small amount of fresh ginger, simmering slowly over low heat. This soup has the effects of fortifying the spleen, supplementing qi, draining dampness, and harmonizing the middle, suitable for the whole family to consume regularly. Chinese yam supplements spleen yin, poria drains spleen dampness—one supplements, one drains; supplementation without stagnation, drainage without damage. Fresh ginger warms the middle and disperses cold, while also removing the greasiness and odor of meat. This soup is mild and gentle, suitable for those with spleen deficiency with exuberant dampness and cold-dampness constitutions alike.
Dried Tangerine Peel and Winter Melon Rind Tea: Take dried tangerine peel and winter melon rind, steep in boiling water as a tea substitute, helping to regulate qi, transform dampness, drain water, and reduce swelling. Dried tangerine peel moves qi, dries dampness, awakens the spleen, and harmonizes the stomach; winter melon rind drains water and reduces swelling. The two combined allow water-dampness qi to exit through the lower jiao. This tea is mild in nature and suitable for regular consumption by those with damp-heat or spleen deficiency with exuberant dampness.
Dietary Contraindications
During the plum rain season, intake of cold and raw fruits, iced beverages, greasy and rich foods, and sweet and cloying foods should be reduced. Cold and raw foods easily damage spleen yang; cold nature causes congealing and stagnation, making the middle jiao like a frozen land where water-dampness is difficult to steam and transform. Greasy, rich foods and sweet, cloying foods easily promote dampness and generate phlegm. TCM holds that "sweetness can generate dampness" and "fatness can promote heat," both of which aggravate dampness encumbering the spleen. In addition, aromatic seasonings such as ginger and dried tangerine peel can be appropriately added during cooking to help awaken the spleen and transform dampness. It should be noted that while dampness-dispelling ingredients are beneficial, they should be used in moderation; excessive use may drain water too much and damage yin fluids, paradoxically causing dry mouth and dry skin.
Key Points for Daily Life Care
The core of daily life care during the plum rain season lies in the nine-character principle: "Avoid external dampness, protect spleen yang, and promote smooth qi movement." Progressing on all four fronts—environment, daily routine, exercise, and emotional wellness—is essential to navigating the damp Jiangnan Huangmei days with ease.
Living Environment and Clothing
Humidity management in the home during the plum rain season is crucial. It is recommended to use a dehumidifier to keep indoor relative humidity between 50%-60%. Pay attention to ventilation in the bedroom, but avoid opening windows during early morning and evening when humidity is highest. Desiccants or bamboo charcoal bags can be placed in wardrobes to absorb moisture and prevent mold. Choose clothing made from breathable cotton and linen fabrics, and avoid wearing clothes that have not dried thoroughly. Change into dry clothing promptly after sweating to prevent dampness from invading the body through the skin. Keep feet dry, and after wading through water on rainy days, promptly wash feet with warm water and dry them.
TCM holds that "dampness is a yin pathogen with a tendency to descend," and the lower part of the body is most susceptible to damage by dampness. Therefore, during the plum rain season, special attention should be paid to keeping the lower limbs warm and dry. In addition, bedding should be regularly aired and sun-dried; otherwise, during nighttime sleep, dampness will slowly seep in through the skin pores, damaging spleen yang over time.
Regular Daily Routine
TCM holds that "the spleen flourishes in late summer," but at the same time, "dampness easily encumbers the spleen." Therefore, adequate sleep helps restore spleen qi. During the plum rain season, one should adapt to the natural rhythms and take appropriate afternoon rests, but should not lie in bed for extended periods—"prolonged lying damages qi"—which paradoxically causes qi movement to become sluggish and dampness to generate internally. TCM emphasizes the "zi-wu sleep": falling asleep before zi hour (11 PM to 1 AM) at night and taking a brief nap during wu hour (11 AM to 1 PM), which best nourishes yang qi and spleen-stomach qi.
It is recommended to maintain 7-8 hours of sleep per day and avoid staying up late, which damages the spleen. Staying up late depletes yin blood; when yin blood is insufficient, yang qi floats upward and deficiency fire generates internally. When combined with dampness, this transforms into damp-heat. Those with insufficient sleep show a marked decline in spleen and stomach transportation and transformation function, with thick greasy tongue coating and bitter, sticky taste in the mouth upon waking—these are telltale signs.
Exercise and Daoyin
Moderate exercise with sweating helps dispel dampness. "Movement generates yang"—exercise can activate yang qi within the body, and when yang qi is freely circulating, water-dampness can be steamed and transformed. Recommended gentle exercises include tai chi, baduanjin (Eight-Section Brocade), and walking, with slight sweating as the appropriate level. These exercises integrate body regulation, breath regulation, and mind regulation into one, aligning with the TCM wellness concept of "physical labor without exhaustion"—cultivating both form and qi, allowing dampness to resolve through sweating.
Exercise time should preferably be during the afternoon when yang qi is relatively abundant. At this time, the body's yang qi is rising toward the surface, and exercise promotes smooth sweating. After exercise, promptly wipe away sweat to avoid catching cold. Avoid profuse sweating; if sweating is excessive, qi escapes with the sweat, paradoxically damaging yang qi and allowing dampness to invade through the weakened defenses. After exercise, do not immediately take a cold shower; wait until sweating has subsided, then bathe with warm water to help harmonize qi and blood.
Emotional Wellness
During the plum rain season, with continuous overcast and rainy days and scarce sunlight, it is most easy for people to feel emotionally low and depressed. TCM holds that "the spleen corresponds to the emotion of pensiveness," and excessive pensiveness damages the spleen. When spleen qi is constrained, transportation and transformation lack power, and dampness more easily generates internally. At the same time, late spring and early summer belong to the season of flourishing wood, and the liver governs free coursing to regulate qi movement. If emotions are depressed, liver qi is not free-flowing; if qi does not move, water does not move, and dampness becomes congested in the middle jiao. Therefore, emotional wellness is equally important as diet and daily routine.
From the perspective of TCM theory, it is recommended to consciously cultivate a "sunny state of mind" during the plum rain season: appropriately increase bright lighting in living spaces, engage in more conversations and heart-to-heart talks with family and friends to free the emotions; listening to music, appreciating calligraphy and painting, and tending flowers and plants—these elegant pursuits can all soothe the liver and resolve depression; reading can shift emotions and transform one's nature, so that when the mind is calm, spleen qi naturally harmonizes. When thoughts are chaotic and one feels oppressed, try to "give rest to thinking"—stop repeatedly dwelling on things—giving spleen and stomach qi a breathing space for self-recovery. When the inner sky is clear and bright, the body's "rainy season" becomes less difficult to endure.