What is Phlegm in TCM?
Phlegm (痰, Tán) is one of the most important pathological concepts in Traditional Chinese Medicine — far broader than the mucus we cough up. In TCM, Phlegm is a pathological product that forms when the Spleen fails to properly transform fluids, creating a thick, sticky substance that can accumulate anywhere in the body and cause a vast array of symptoms.
The famous TCM saying captures its significance: “Phlegm is the mother of a hundred diseases” (百病皆由痰作祟). Unlike Western medicine which limits phlegm to respiratory mucus, TCM recognizes both visible Phlegm (sputum, nasal discharge) and invisible Phlegm (lumps, nodules, mental fog, numbness, tumors).
Key principle: “The Spleen is the source of Phlegm; the Lung is the receptacle of Phlegm.” Phlegm originates from digestive weakness but manifests in many organs.
Poor diet / Overthinking / Spleen weakness
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Spleen cannot transform fluids properly
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Fluids accumulate → become turbid → become Dampness
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Dampness condenses → becomes Phlegm
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Phlegm can travel anywhere via meridians
Predisposing Factors
| Factor | Mechanism |
|---|
| Spleen Qi deficiency | Weak digestion can’t process fluids |
| Overeating rich, greasy, sweet food | Overwhelms Spleen’s transformative capacity |
| Damp environment | External Dampness worsens internal Dampness |
| Kidney Yang deficiency | Can’t warm the Spleen; water metabolism fails |
| Lung Qi deficiency | Can’t distribute fluids properly |
| Emotional stress | Qi stagnation impedes fluid movement |
| Lack of exercise | Sluggish Qi allows fluid accumulation |
Visible vs. Invisible Phlegm
Visible Phlegm (有形之痰)
Phlegm that can be seen, coughed up, or otherwise observed:
| Manifestation | Location | Examples |
|---|
| Sputum | Lungs / Respiratory | Coughed-up mucus (white, yellow, green) |
| Nasal discharge | Nose / Sinuses | Runny nose, post-nasal drip |
| Vomiting | Stomach | Nausea with mucoid vomit |
| Thick saliva | Mouth | Stringy, difficult-to-swallow saliva |
| Loose stools with mucus | Intestines | Mucous in bowel movements |
Invisible Phlegm (无形之痰)
Phlegm that cannot be directly seen but causes significant symptoms:
| Manifestation | Organ/System | Examples |
|---|
| Nodules and lumps | Thyroid, lymph, breast | Goiter, enlarged lymph nodes, breast lumps |
| Mental fog | Brain / Heart | Confusion, poor concentration, dizziness |
| Numbness and tingling | Meridians / Nerves | Numb limbs, facial paralysis |
| Obesity (puffy type) | Whole body | Soft, spongy fat with water retention |
| Palpable masses | Abdomen | Abdominal masses, ovarian cysts |
| Skin conditions | Skin | Abscesses that don’t resolve, chronic skin nodules |
| Mental disorders | Heart / Shen | Mania, seizures, bizarre behavior (Phlegm misting the Heart) |
| Dizziness and vertigo | Head | ”Wind-Phlegm” rising to the head |
| Nausea without vomiting | Stomach | Constant urge to vomit but nothing comes up |
Phlegm Pattern Differentiation
1. Cold Phlegm (寒痰)
| Feature | Description |
|---|
| Sputum | White, clear, watery, easy to expectorate |
| Accompanying signs | Cold limbs, pale face, aversion to cold |
| Tongue | Pale with white, wet, slippery coat |
| Pulse | Slow, slippery or tight |
| Mechanism | Yang deficiency + Cold condenses fluids into Phlegm |
| Treatment | Warm the Middle, transform Cold Phlegm |
| Key formula | Ling Gan Wu Wei Jiang Xin Tang |
| Key herbs | Gan Jiang (dried ginger), Bai Jie Zi, Ban Xia |
2. Hot Phlegm (热痰)
| Feature | Description |
|---|
| Sputum | Yellow, thick, sticky, difficult to expectorate |
| Accompanying signs | Fever, thirst, red face, irritability |
| Tongue | Red with yellow, thick, greasy coat |
| Pulse | Rapid, slippery |
| Mechanism | Heat condenses fluids into thick, yellow Phlegm |
| Treatment | Clear Heat, transform Hot Phlegm |
| Key formula | Qing Qi Hua Tan Wan |
| Key herbs | Huang Qin, Gua Lou, Bei Mu, Zhu Ru |
3. Dry Phlegm (燥痰)
| Feature | Description |
|---|
| Sputum | Very scanty, sticky, hard to cough up, may have blood streaks |
| Accompanying signs | Dry mouth, dry throat, dry cough |
| Tongue | Red, dry, with little coat |
| Pulse | Fine, rapid |
| Mechanism | Dryness or Yin deficiency fails to moisten |
| Treatment | Moisten Lung, transform Dry Phlegm |
| Key formula | Bei Mu Gua Lou San |
| Key herbs | Bei Mu, Gua Lou, Mai Men Dong, Nan Sha Shen |
4. Phlegm-Dampness (痰湿)
| Feature | Description |
|---|
| Sputum | Copious, white, easy to expectorate |
| Accompanying signs | Heaviness, bloating, obesity, sticky mouth |
| Tongue | Swollen with thick white greasy coat |
| Pulse | Slippery |
| Mechanism | Spleen deficiency produces Dampness which congeals to Phlegm |
| Treatment | Strengthen Spleen, drain Dampness, transform Phlegm |
| Key formula | Er Chen Tang (Two-Cured Decoction) |
| Key herbs | Ban Xia, Chen Pi, Fu Ling, Zhi Gan Cao |
5. Wind-Phlegm (风痰)
| Feature | Description |
|---|
| Key symptom | Sudden dizziness, vertigo, or stroke symptoms |
| Accompanying signs | Numbness, spasms, facial paralysis, headache |
| Tongue | May be deviated, with greasy coat |
| Pulse | Wiry, slippery |
| Mechanism | Internal Wind stirs up Phlegm, driving it to the head |
| Treatment | Extinguish Wind, transform Phlegm |
| Key formula | Ban Xia Bai Zhu Tian Ma Tang |
| Key herbs | Tian Ma, Ban Xia, Bai Zhu, Ze Xie |
6. Phlegm Obstructing the Heart (痰迷心窍)
| Feature | Description |
|---|
| Key symptom | Mental confusion, seizures, loss of consciousness |
| Accompanying signs | Unconsciousness, foaming at mouth, incoherent speech |
| Tongue | Thick greasy coat |
| Pulse | Slippery, wiry |
| Mechanism | Phlegm blocks the Heart orifices, misting the Shen |
| Treatment | Open the orifices, resolve Phlegm |
| Key formula | Di Tan Tang (Phlegm-Flushing Decoction) |
Phlegm by Organ
| Organ | Phlegm Effect | Symptoms |
|---|
| Lung | Blocks airways | Cough, wheezing, asthma, sputum |
| Spleen | Originates here | Bloating, nausea, poor appetite, fatigue |
| Heart | Mists the Shen | Confusion, mania, seizures, insomnia |
| Liver / Gallbladder | Combines with Qi stagnation | Plum-pit qi (feeling of lump in throat), irritability |
| Kidney | Fluid metabolism worsens | Edema, lower back pain, frequent urination |
| Meridians | Blocks Qi and Blood | Numbness, heaviness, paralysis, joint pain |
| Skin | Forms nodules | Lipomas, sebaceous cysts, chronic skin conditions |
Foods That Aggravate Phlegm
| Food | Why |
|---|
| Dairy products | TCM considers milk and cheese “Damp-Phlegm forming” |
| Sweets and sugar | Damage Spleen, create Dampness |
| Greasy, fried food | Difficult to digest, generates Damp-Phlegm |
| Cold, raw foods | Impair Spleen transformation |
| Excessive fruit | Too much moisture, especially tropical fruits |
| Alcohol | Creates Damp-Heat which can become Phlegm |
Foods That Resolve Phlegm
| Food | Effect |
|---|
| Radish (white) | Transforms Phlegm, moves Qi downward |
| Pear | Moistens and dissolves Dry Phlegm |
| Tangerine peel (Chen Pi) | The classic Phlegm-resolving herb/food |
| Ginger | Warms and transforms Cold Phlegm |
| Kelp and seaweed | Resolve Phlegm nodules (especially thyroid) |
| Water chestnut | Clears Hot Phlegm |
| Coix seed (Yi Yi Ren) | Drains Dampness, supports Spleen |
Key Takeaways
- Phlegm in TCM is far broader than respiratory mucus — it includes invisible accumulations anywhere in the body
- “The Spleen is the source of Phlegm” — digestive weakness is the root cause
- Six main types: Cold, Hot, Dry, Damp, Wind, and Heart-obstructing Phlegm
- Invisible Phlegm can cause nodules, mental fog, obesity, and neurological symptoms
- Sputum color and texture are key diagnostic tools (white=Cold, yellow=Heat, sticky=Dry)
- Diet is central to both causing and resolving Phlegm
Disclaimer: This article is for educational purposes only. Chronic phlegm conditions, nodules, or masses require evaluation by a qualified healthcare professional.
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