What is Phlegm and its Harms in TCM?

In my clinical practice, I’ve come to deeply realize one thing: nearly 9 out of 10 people have issues related to phlegm and dampness. Yet many don’t even know it. They might think phlegm is just that sticky stuff in the throat, but in Traditional Chinese Medicine (TCM), the concept of “phlegm” goes far beyond what you can cough out.

What Is Phlegm in TCM?

Phlegm, from a TCM perspective, is not just respiratory mucus. It refers to pathological metabolic by-products—materials the body cannot fully transform and absorb due to weak or overloaded digestion (primarily the Spleen system). These materials accumulate and transform into “phlegm,” lingering in the body and causing a wide variety of symptoms.

Aside from the classic throat phlegm, here are 9 other signs of internal phlegm:

1. Excessive drooling in children

2. Sticky or abnormal vaginal discharge

3. Mucus in stool or sticky bowel movements

4. Cloudy or foamy urine

5. Thick yellow nasal discharge

6. Excessive earwax or eye discharge

7. Oily skin, large pores

8. Nodules, cysts, fatty tumors

9. High cholesterol, fatty liver, thick blood

These may all seem unrelated, but many are different manifestations of internal phlegm and dampness.

Where Does Phlegm Come From?

In TCM, we often say: “The Spleen is the source of phlegm, the Lungs are its storage.” This means that when the digestive system—especially the Spleen—is weak or overloaded, it fails to fully metabolize food and fluids. Over time, this leads to the production of phlegm and dampness.

Phlegm is rarely formed overnight. It accumulates through years of poor eating habits, emotional stress, lack of exercise, and irregular routines, eventually leading to chronic health problems.

Why Is Phlegm So Harmful?

Once phlegm is formed, it can:

• Block the meridians, causing pain, numbness, and frozen shoulders

• Disrupt digestion, causing bloating, poor appetite, and sticky stool

• Cloud the mind and emotions, resulting in poor sleep, brain fog, or depression

• Promote chronic inflammation, cysts, and nodules

• Increase the risk of high cholesterol, fatty liver, and blood viscosity

People with different complaints—pain here, a cyst there, sluggish energy—may actually all be suffering from the same root issue: phlegm-dampness.

Can Diet Alone Clear Phlegm?

A common question I get is: “Can I just eat lighter to get rid of phlegm?”

The answer is: Not always. For many people, phlegm has been building up for years and is already deeply entrenched in the system. Dietary changes alone are often not enough.

The recommended approach is:

1. Start with professional TCM treatment—herbs and acupuncture to clear internal phlegm

2. Then maintain results with proper diet and lifestyle

This way, you address both the root and the branches of the issue.

9 Common Phlegm-Producing Foods

TCM classics mention: “Rich, greasy, and heavy foods generate phlegm.”
Here are the worst offenders:

1. Dairy products (milk, cheese, cream, butter)

2. Fried foods (e.g. fried chicken, chips)

3. Sugary treats (cakes, candies, bubble tea)

4. Alcohol—especially beer and sweet liquors

5. Baked goods with cream or butter

6. Fatty red meats

7. Organ meats

8. Processed snacks and junk food

9. Ice-cold drinks or too much raw food (which weakens the Spleen)

Daily Tips to Help Reduce Phlegm

• Eat light, warm, and cooked meals

• Incorporate foods like winter melon, coix seeds, white radish, and aged tangerine peel

• Avoid cold drinks and keep the abdomen warm

• Check your tongue coating—if it’s thick and greasy, phlegm-dampness is likely

• Even if your tongue looks normal, a TCM practitioner can confirm via pulse diagnosis

Final Thoughts:

Phlegm and dampness are often silent culprits behind many modern chronic issues—from fatigue to inflammation to metabolic disorders.
To truly regain your vitality, you need to first eliminate the internal phlegm through targeted TCM treatment, then use proper nutrition and lifestyle as maintenance.

It’s not just about cutting dairy or sugar. It’s about restoring your body’s ability to transform and transport fluids—the core function of your Spleen and digestive system in TCM.