As soon as summer arrives and temperatures skyrocket, do you also often feel exhausted all over, listless, and even as if you have heatstroke? Many people share similar questions: Why does the body feel so tired when the weather is hot? Is this state a normal phenomenon, or is the body sending a signal?
From the perspective of traditional Chinese medicine, exhaustion all over caused by high summer temperatures is often related to "summerheat-dampness" and "dual deficiency of qi and yin." Hot summer weather causes profuse sweating, and sweat is the fluid of the heart. Excessive sweating easily consumes the body's qi and fluids, leading to insufficient qi and yin. At the same time, summer dampness is heavy, and dampness pathogens obstruct the spleen and stomach, which can also make people feel heavy, weak, and mentally foggy. This state is not the same as heatstroke, but it does have similarities—heatstroke is a direct attack by summerheat, whereas fatigue is more of a chronic response of the body to high temperatures.
The Suwen · Discussion of Heat Diseases states: "Sweat is essence and qi." Summerheat forces fluids to leak outward, and excessive sweating damages fluids and consumes qi. Fluids can carry qi, and when qi escapes with sweat, shortness of breath and fatigue appear; when fluids are damaged, there is loss of moistening, so there is dry mouth with desire to drink and scanty urine. Dampness is the dominant qi of late summer. The spleen prefers dryness and dislikes dampness. When dampness traps the middle jiao, transformation and transportation lose their authority, and the essential substances of water and grain cannot be distributed to the limbs and muscles, hence heaviness of the body, laziness, and desire to lie down. This is precisely where the core pathogenesis of summer fatigue lies.
In TCM theory, the spleen and stomach are the foundation of the acquired constitution and the source of qi and blood generation. Zusanli, also known as Xialing or Sanli, is located on the anterior-lateral aspect of the lower leg, 3 cun below Dubi, one finger-breadth from 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 says: "When pathogens are in the spleen and stomach, there is muscle pain. If yang qi is in excess and yin qi is insufficient, there is heat in the center and frequent hunger; if yang qi is insufficient and yin qi is in excess, there is cold in the center, bowel sounds, and abdominal pain... all are regulated at Zusanli." In summer fatigue, the root deficiency is mainly qi deficiency, and Zusanli is closely related to the transformation and transportation of the spleen and stomach and the generation of qi and blood.
From the perspective of causes, summer fatigue has both internal and external aspects. The external cause is attributed to the steaming combination of summerheat and turbid dampness, or to exposure to wind and craving coolness. The internal cause is related to a constitution with weak spleen and stomach and insufficient qi and yin. The disease location is mainly in the spleen and stomach, involving the heart and lungs. Summerheat is a yang pathogen; its nature is rising and dispersing, and it easily consumes qi and damages fluids. Dampness is a yin pathogen; its nature is heavy, turbid, sticky, and stagnant, and it easily traps and obstructs clear yang. When summerheat and dampness combine, they cause dysfunction of middle jiao transformation and transportation, clear yang fails to rise, and turbid yin fails to descend, resulting in limb fatigue, mental tiredness, heaviness of the head, and clouded thinking. The nature of the disease is generally a mixture of deficiency and excess—the root deficiency is mainly qi deficiency and depletion of yin fluids, while the branch excess is chiefly summerheat, dampness, heat, and turbidity. In terms of disease tendency, at the beginning the pathogen is in the wei and qi levels. If it drags on without recovery, qi and yin depletion worsens day by day, and dampness-turbidity may also generate phlegm-heat, which can rise and cloud the clear orifices, producing transformed patterns such as dizziness, palpitations, and chest oppression. Therefore, it should not be taken lightly just because it is "only fatigue."
So how do you distinguish ordinary summer fatigue from true heatstroke? Heatstroke usually comes with acute symptoms such as high fever, burning skin, and confusion, whereas feeling exhausted all over when summer temperatures are high, as if you have heatstroke, is more often a persistent sense of fatigue that may be accompanied by poor appetite, dry mouth, and sticky stools. If you only feel tired and have no other acute discomfort, it most likely falls within the category of summerheat-dampness encumbering the spleen or dual deficiency of qi and yin.
Further careful pattern identification helps determine the direction of regulation. In those with summerheat-dampness encumbering the spleen, besides fatigue, there is often soreness and heaviness of the limbs, heaviness of the head as if wrapped, stuffiness and oppression in the epigastrium and abdomen, sticky mouth without thirst or thirst without desire to drink, loose and unsmooth stools, a white greasy or yellow greasy tongue coating, and a soggy, slippery, or soggy, moderate pulse. In those with dual deficiency of qi and yin, there is mental fatigue and lack of strength, shortness of breath and disinclination to speak, thirst with desire to drink, dry throat and lips, heat in the palms and soles, vexation and insomnia, and scanty urine, with a red tongue with little fluid or a pale tongue with little coating, and a thin, weak or thin, rapid pulse. Both patterns have fatigue, but the former is marked by "heaviness, stuffiness, and greasy coating," while the latter is marked by "shortness of breath, dry mouth, and a red tongue with little fluid." These are the key points of differentiation. If there is also unsurfacing body heat and sticky sweating, it belongs to summerheat-dampness damaging the wei level; if there is also palpitation, spontaneous sweating, and a scattered, large pulse, then qi and yin are about to desert, approaching a dangerous turn of heatstroke, and medical help must be sought immediately.
When summerheat and dampness are abundant, they easily encumber spleen yang. Yinlingquan, also known as Yinzhilingquan, is located on the medial side 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 Zhenjiu Dacheng says it "governs cold in the abdomen, lack of desire for food, fullness below the ribs, water swelling and hardness of the abdomen, panting and inability to lie down." Dampness is a yin pathogen, heavy and turbid in nature. As the He-Sea point of the Spleen Meridian and belonging to water in the five phases, Yinlingquan is closely related to water-dampness metabolism in the body and is often mentioned in the pattern-based diagnosis and treatment of summer fatigue.
In light of this condition, are there any daily regulation methods? TCM emphasizes "nourishing yang in spring and summer." The focus of summer care is to strengthen the spleen and drain dampness, and to supplement qi and nourish yin. In diet, one may appropriately eat more light, easily digestible foods, such as mung bean soup, winter melon soup, and coix seed porridge, which help clear heat and drain dampness. At the same time, avoid excessive craving for cold, such as iced drinks and air conditioning set too low, both of which may aggravate dampness in the body.
"Nourishing yang in spring and summer" comes from the Suwen · Great Treatise on Regulating the Spirit According to the Four Qi, which states: "The yin and yang of the four seasons are the root of all things. Therefore, the sage nourishes yang in spring and summer, and nourishes yin in autumn and winter, in order to follow their root." Its essential meaning is that in spring and summer yang qi rises and develops, and the human body must follow its growing tendency so that yang qi reaches outward and is not suppressed. However, in summer, yang heat floats outward, while middle yang is instead prone to insufficiency. If one craves coolness and drinks cold, internal yang is damaged and dampness-turbidity is generated internally. Therefore, "nourishing yang" is by no means blind warming and tonification, but rather protecting through diet and daily living