In March, spring chill lingers, and the weather alternates between warm and cold. In the north, heating has not yet stopped, while in the south, the returning dampness of spring gradually rises. Many people begin to feel as if something is stuck in their throat—unable to cough it all up or spit it all out. White thin phlegm comes in endless batches, or yellow thick phlegm blocks the chest, making one restless and uneasy. Why does phlegm suddenly increase in this season? What bodily signals are hidden behind this?
Classic Layer-by-Layer Interpretation: Where Does Phlegm Come From, and How Is It Differentiated?
"The spleen is the source of phlegm production; the lung is the container that stores phlegm." — Huangdi Neijing
This saying is almost universally known in TCM clinical practice, yet its deeper meaning is often overlooked. The spleen governs the transformation and transportation of water-dampness, functioning like the body's "drainage system." If the spleen's function weakens, water-dampness cannot be metabolized normally and gradually congeals into "phlegm." The lung governs diffusion and descending, serving as the temporary "container" where phlegm collects. Therefore, the problem of excess phlegm often does not originate in the lung, but in the spleen.
In the TCM meridian theory, there is an acupoint closely related to phlegm-dampness—Fenglong. Fenglong is the luo-connecting point of the Foot Yangming Stomach Meridian, diverging to the Spleen Meridian. It is located on the anterolateral aspect of the lower leg, 8 cun above the tip of the lateral malleolus, 1 cun lateral to Tiaokou, and two finger-breadths lateral to the anterior crest of the tibia. Because it connects the spleen and stomach meridians and has the function of moving the middle jiao and transforming phlegm-turbidity, TCM has long held the saying "Fenglong transforms phlegm." The Yulong Ge states: "For excess phlegm, one should seek Fenglong," demonstrating its important significance in regulating phlegm-fluid patterns.
White thin phlegm, in TCM view, is mostly related to "cold" or "dampness." In spring, yang qi begins to rise, but cold qi has not yet fully retreated. If the body's yang qi is insufficient and the spleen's transforming and transporting capacity cannot keep up, water-dampness easily becomes thin white phlegm. This type of phlegm is often clear and thin, large in quantity, and easy to cough up but never fully cleared. Clinically, these individuals often present with aversion to cold, cold hands and feet, and a white greasy tongue coating.
Yellow thick phlegm is different. Yellow is a sign of heat, and thickness indicates that the phlegm has been "refined"—like water-dampness dried by fire, becoming sticky and viscous "phlegm-turbidity." This condition is mostly related to "heat" or "dryness." In spring, wind pathogen dominates, and when wind combines with heat, it easily damages lung fluids, causing phlegm to turn yellow and thick. These individuals often feel dry throat, sticky phlegm that is difficult to cough up, and may even have mild fever or sore throat.
For the lung heat manifestation associated with yellow thick phlegm, one may consider the Yuji acupoint of the Hand Taiyin Lung Meridian. Yuji is located on the lateral side of the hand, at the midpoint of the radial side of the first metacarpal bone, at the junction of the red and white flesh. It is the ying-spring point of the Lung Meridian. The Nan Jing states, "Ying points govern bodily heat," so this point has an intrinsic connection to heat patterns of the Lung Meridian. During spring when wind-heat invades the lung, the dispersing and clearing-moistening functions of the meridian where this point lies are often emphasized by TCM physicians.
Clinically, one must first differentiate: is cold-dampness predominant, or heat-dryness predominant? The two require completely different regulatory directions. Those with white thin phlegm should warm and transform cold-dampness; those with yellow thick phlegm should clear heat and moisten dryness. If one indiscriminately uses phlegm-transforming medicines without distinguishing, it may actually worsen the problem.
Modern people lead fast-paced lives with irregular diets, and many remain in a state of "spleen deficiency" for extended periods. Combined with the significant climate changes in spring and marked indoor-outdoor temperature differences, the body's regulatory capacity is easily thrown off balance. White thin phlegm is more commonly seen in those who sit for long periods, exercise little, and enjoy cold drinks; yellow thick phlegm is more often seen in those who stay up late, prefer spicy foods, and are under great stress. These group characteristics are worth every reader's reflection in relation to their own habits.
Daily Care Starting from Life Details to Help the Body "Transform Phlegm"
Since the root of phlegm lies in the spleen, the focus of care should naturally be on the spleen and stomach. Spring is the season when liver qi rises, and liver wood restrains spleen earth. If emotions fluctuate greatly and one thinks excessively, spleen-stomach function is more easily affected. Therefore, maintaining a cheerful mood can help reduce phlegm production to some extent. Walking, listening to music, and chatting with friends are all good ways to regulate.
When discussing spleen-stomach care, Zusanli is an indispensable classic acupoint. Zusanli, also known as Xialing or Sanli, belongs to the Foot Yangming Stomach Meridian. It is the he-sea point of the Stomach Meridian and the lower he-sea point of the stomach. It is located on the anterolateral aspect of the lower leg, 3 cun below Dubi, one finger-breadth from the anterior crest of the tibia. This point is closely related to the transforming and transporting functions of the spleen and stomach. The Lingshu states: "When pathogen is 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 middle and frequent hunger; if yang qi is insufficient and yin qi is in excess, there is cold in the middle with bowel sounds and abdominal pain... all are regulated by Zusanli." This demonstrates its important theoretical value in regulating middle jiao qi movement and transforming water-dampness.
Dietarily, those with white thin phlegm may appropriately choose warm-natured ingredients such as ginger, aged tangerine peel, and scallion white. Ginger helps warm the middle and dispel cold; aged tangerine peel can regulate qi and transform phlegm. Steeping a few slices in water or adding them to cooking can help alleviate cold-dampness type excess phlegm. Those with yellow thick phlegm should choose clear-moistening ingredients such as pear, white radish, and water chestnut. Pear can moisten the lung and clear heat; white radish can promote digestion and transform phlegm. Consuming these in moderation helps alleviate heat-dryness symptoms.
However, it should be noted that each person's constitution is different, and the same ingredient may have completely opposite effects on different people. For example, if someone with white thin phlegm mistakenly eats pear, it may worsen cold-dampness; if someone with yellow thick phlegm mistakenly uses ginger, it may reinforce heat. Therefore, readers are advised to observe the color, texture, and accompanying symptoms of their phlegm before attempting any dietary adjustment, and to consult a licensed TCM physician when necessary, so that a professional can provide individualized recommendations based on pattern differentiation.
Spring has large temperature differences between morning and evening, so keeping warm is especially important. The neck and back in particular are areas where yang qi converges; exposure to cold can easily affect lung function and worsen excess phlegm. Wearing a silk scarf when going out, or avoiding direct air conditioning indoors, are simple and effective care measures.
Regarding exercise, appropriate activity helps qi and blood circulation and strengthens the spleen's transforming and transporting capacity. However, spring exercise should not be too intense, lest it consume and damage yang qi. Gentle exercises such as brisk walking, taijiquan, and baduanjin, lasting 20-30 minutes each session, have a supportive effect on improving excess phlegm. Specific plans should be determined by a licensed TCM physician based on individual constitution, and one must not blindly imitate others.
Frequently Asked Questions
1. Between white thin phlegm and yellow thick phlegm, which is more serious?
There is no absolute distinction of severity between the two; the key lies in the underlying pathogenesis. White thin phlegm is mostly related to cold-dampness, while yellow thick phlegm is mostly related to heat-dryness. If phlegm color changes from white to yellow, it may indicate a change in the condition; conversely, if it changes from yellow to white, it may suggest that the heat manifestation is diminishing. However, specific judgment requires comprehensive information including tongue coating and pulse presentation. Consulting a professional physician is recommended.
2. Why do some people with excess phlegm need warming and tonifying, while others need clearing and draining?
This is precisely the manifestation of TCM's "treating the same disease with different methods." Excess phlegm is only a symptom; the root may be spleen deficiency, lung heat, kidney yang insufficiency, or other different factors. If white thin phlegm belongs to spleen yang deficiency, warming and tonifying can help yang transform dampness; if yellow thick phlegm belongs to lung heat, clearing and draining can clear heat and moisten dryness. The regulatory directions are opposite, but the goal is the same—to restore the body's balance.
3. With excess phlegm in spring, can I just buy some phlegm-transforming medicine on my own?
Self-medication is not recommended. Most phlegm-transforming medicines on the market target wind-heat or wind-cold types, but the pathogenesis of spring excess phlegm often involves complex factors such as cold-dampness, damp-heat, and qi stagnation. Using the wrong medicine may mask the real problem or even worsen the condition. It is advisable to first adjust through diet and daily routine; if symptoms persist, consult a formal medical institution.
4. Is there a direct relationship between excess phlegm and seasonal changes?
There is a close relationship. Spring climate is changeable, and wind pathogen dominates, easily affecting the lung's diffusion function. At the same time, spring liver qi rises; if liver qi is excessive, it restrains the spleen and stomach, leading to impaired water-dampness transformation and transportation, thereby generating phlegm. Therefore, spring excess phlegm is not coincidental but a response of the body to seasonal changes. Adjusting diet and daily routine in accordance with the solar terms is an effective way to reduce excess phlegm.