Six Excesses (六淫) Variable Yang External & Internal

The Six Excesses (Six Evils)

六淫 Liù Yín
Also known as: Six Evils · Six Pernicious Influences · Six External Pathogens · Six Climatic Factors · Liu Xie (六邪)

The Six Excesses (Liu Yin) are six external pathogenic factors—Wind, Cold, Summer-Heat, Dampness, Dryness, and Fire—that originate from abnormal climatic changes and can invade the body to cause disease when the body's defenses are weakened.

Key Properties

Seasonal correspondence Environmental origin Can combine with other pathogens Can transform into other pathogenic natures Primarily affects exterior before interior Regional variation in prevalence

Body Layers

Wei (Defensive)

六淫

Liù Yín

The Six Excesses (Six Evils)

Nature & Properties

Thermal Nature

Variable

Yin-Yang

Yang

Educational content · Consult qualified TCM practitioners for diagnosis and treatment

Overview

The Six Excesses (六淫, Liù Yín) represent the primary external causes of disease in Traditional Chinese Medicine. They consist of six environmental factors: Wind (风 Fēng), Cold (寒 Hán), Summer-Heat (暑 Shǔ), Dampness (湿 Shī), Dryness (燥 Zào), and Fire/Heat (火 Huǒ).

Under normal circumstances, these are simply the 'Six Qi' (六气)—natural climatic variations that the body can adapt to without harm. However, when these climatic forces become excessive, occur out of season, change too abruptly, or when a person's defensive energy (正气 Zhèng Qì) is weakened, they transform into disease-causing pathogens. The Chinese character '淫' (yín) implies 'excess' or 'overflowing,' indicating that these are normal forces that have become pathological through excess.

The Six Excesses are considered 'external' pathogens because they typically invade the body from outside through the skin, nose, or mouth. They are closely tied to seasonal patterns—Wind predominates in Spring, Summer-Heat in Summer, Dampness in Late Summer, Dryness in Autumn, and Cold in Winter—though any pathogen can appear in any season under unusual conditions.

Historical Context

The concept of the Six Excesses has roots in the earliest Chinese medical texts, evolving over two millennia of observation and clinical practice.

The foundational text is the Huang Di Nei Jing (Yellow Emperor's Classic of Internal Medicine), compiled during the Warring States period (475-221 BCE). The Su Wen chapter 74 famously states that all diseases arise from Wind, Cold, Summer-Heat, Dampness, Dryness, and Fire. However, the specific term '六淫' (Liù Yín) first appeared in the Song Dynasty work San Yin Ji Yi Bing Zheng Fang Lun (Treatise on the Three Categories of Pathogenic Factors) by Chen Wuze (1174 CE), who systematized disease causes into three categories: external, internal, and neither external nor internal.

The Six Excesses theory was further refined through the development of the Shang Han (Cold Damage) school based on Zhang Zhongjing's Shang Han Lun (c. 220 CE), and later the Wen Bing (Warm Disease) school in the Qing Dynasty. Modern TCM has integrated this classical framework while also recognizing that the Six Excesses encompass what Western medicine would identify as infectious agents, environmental stressors, and immunological challenges.

Defining Characteristics

External origin

外感性

The Six Excesses primarily originate from the external environment and invade the body from outside, entering through the skin, nose, or mouth. This distinguishes them from internal pathogens that arise from organ dysfunction.

Seasonal correspondence

季节性

Each pathogen has a dominant season: Wind in Spring, Summer-Heat in Summer, Dampness in Late Summer, Dryness in Autumn, and Cold in Winter. However, abnormal climate can produce any pathogen in any season.

Regional variation

地域性

Geographic location influences disease patterns. Northwestern regions see more Cold and Dryness diseases; southeastern coastal areas have more Dampness and Heat conditions.

Can combine together

相兼性

The Six Excesses can invade singly or in combination. Common combinations include Wind-Cold, Wind-Heat, Wind-Dampness, Damp-Heat, and Cold-Dampness. Multiple pathogens often attack simultaneously.

Mutual transformation

转化性

Under certain conditions, one pathogen can transform into another. Cold constrained in the body may transform into Heat; prolonged Dampness may generate Heat or transform into Dryness. This depends on constitution and treatment.

Entry Routes

The Six Excesses typically invade the body through external routes, which is why they are called 'external pathogens' (外邪). The primary entry points include:

  • Skin and pores (腠理 Còu Lǐ): Wind, Cold, and Dampness commonly penetrate through the skin surface, especially when pores are open from sweating or when defensive Qi is weak
  • Nose and mouth: Respiratory invasion is common for Wind pathogens, which may carry Cold or Heat
  • Direct exposure: Summer-Heat enters through prolonged exposure to extreme heat; Dryness affects the Lungs through breathing dry air

Living conditions and environment also determine pathogen invasion—residing in damp housing can cause Dampness invasion regardless of season, while working in cold environments predisposes to Cold invasion.

Progression Pattern

Body Layers Affected

Wei (Defensive)

The Six Excesses typically follow a progression from the exterior to the interior of the body, though the specific pattern varies by pathogen:

  • Exterior to Interior: Initial invasion affects the Wei (Defensive) level, then progresses to the Qi level, Ying (Nutritive) level, and finally the Blood level if untreated
  • Surface to Organs: Pathogens first affect skin, muscles, and meridians before penetrating to affect the Zang-Fu organs
  • Transformation: Cold pathogens may transform into Heat when they penetrate deeper or encounter a constitution with excess Yang; Dampness may transform into Dryness or Heat over time

Wind is considered the 'leader of the hundred diseases' (百病之长) because it often carries other pathogens into the body. Summer-Heat is unique in that it often directly affects the interior without a clear exterior stage. The Four Levels (Wei-Qi-Ying-Xue) framework developed in the Qing Dynasty describes this progression in detail for warm-febrile diseases.

Clinical Relevance

The Six Excesses remain central to TCM diagnosis and treatment of acute illnesses, particularly infectious and environmentally-related diseases.

Clinical applications include:

  • Upper respiratory infections are commonly diagnosed as Wind-Cold or Wind-Heat invasion, guiding the choice between warming-dispersing or cooling-dispersing treatments
  • Digestive complaints in humid seasons are often attributed to Damp-Heat or Spleen Dampness
  • Seasonal allergies are frequently treated as Wind invasion, using Wind-expelling herbs and points
  • Arthritic conditions (Bi syndrome) are classified according to the predominant pathogen—Wind, Cold, or Dampness

Modern research has validated many classical observations. Studies have shown correlations between weather patterns and disease incidence that align with Six Excesses theory. The framework continues to provide practical guidance for prevention—patients are advised to protect against seasonal pathogens and maintain strong defensive Qi through lifestyle, diet, and when appropriate, preventive herbal formulas.

Common Manifestations

Wind (风 Fēng) manifestations

Rapid onset, symptoms that move around or change quickly, headache, aversion to wind, itching, tremors, convulsions, dizziness. Wind is called 'the leader of the hundred diseases' because it often carries other pathogens into the body.

Cold (寒 Hán) manifestations

Chills, aversion to cold, cold limbs, pallor, clear watery discharges, pain that is fixed and cramping, contraction of muscles and tendons, slow or stagnant conditions. Cold damages Yang Qi and causes things to contract.

Summer-Heat (暑 Shǔ) manifestations

High fever, profuse sweating, intense thirst, red face, restlessness, concentrated dark urine, exhaustion. Unique to summer, it depletes Qi and fluids rapidly and often combines with Dampness.

Dampness (湿 Shī) manifestations

Heavy sensation in body and limbs, sticky or greasy discharges, turbid urine, loose stools, poor appetite, swelling, skin conditions with oozing. Dampness is heavy, lingering, and difficult to resolve.

Dryness (燥 Zào) manifestations

Dry skin, cracked lips, dry nose and throat, dry cough with little sputum, constipation with dry stools, scanty urine. Dryness injures body fluids and primarily affects the Lungs.

Fire/Heat (火 Huǒ) manifestations

High fever, red face and eyes, thirst for cold drinks, irritability, dark yellow urine, constipation, skin eruptions, bleeding. Fire flares upward, consumes fluids, and can stir Wind or move Blood recklessly.

Tongue Manifestations

Tongue changes vary according to which of the Six Excesses is present:

  • Wind: Tongue may tremble or deviate; coating may be thin white or thin yellow
  • Cold: Pale tongue body, moist white coating, sometimes thick white coating
  • Summer-Heat: Red tongue, possibly with a dry yellow coating; may show cracks from fluid loss
  • Dampness: Swollen tongue with teeth marks, thick greasy coating (white for Cold-Damp, yellow for Damp-Heat)
  • Dryness: Dry tongue with little or no coating, may show cracks; red if transformed to Heat
  • Fire/Heat: Red to deep red tongue body, yellow or dry coating; may have red points indicating Blood Heat

Pulse Manifestations

Each of the Six Excesses produces characteristic pulse qualities:

  • Wind: Floating (浮 Fú) pulse, often at the superficial level; may be rapid if Wind-Heat
  • Cold: Tight (紧 Jǐn) or slow (迟 Chí) pulse; deep and tight if Cold has penetrated inside
  • Summer-Heat: Surging (洪 Hóng) or rapid (数 Shuò) pulse; may become weak and thready from Qi and fluid exhaustion
  • Dampness: Slippery (滑 Huá) or soft/soggy (濡 Rú) pulse; slow and moderate quality
  • Dryness: Thin (细 Xì) pulse, possibly rough/choppy (涩 Sè) indicating fluid deficiency
  • Fire/Heat: Rapid (数 Shuò) and forceful pulse; may be flooding (洪 Hóng) in severe cases

Common Pathogen Combinations

The most common external pathogen combination. Wind opens the pores while Cold penetrates. Manifests as aversion to cold, headache, body aches, nasal congestion, and absence of sweating. Commonly seen in the common cold during cold weather.

Wind carries Heat into the body. Presents with fever, slight aversion to wind, sore throat, headache, yellow nasal discharge, and mild sweating. Common in Spring or when Cold transforms to Heat.

A sticky, persistent combination. Causes heavy limbs, poor appetite, loose smelly stools, yellow greasy tongue coating, skin conditions with oozing, and urinary difficulties. Common in Late Summer and in southern climates.

Wind-Cold-Dampness (风寒湿)

Combined with Dampness as a pathogen

The classic cause of Bi syndrome (painful obstruction). Creates joint pain, stiffness, heaviness, and limited mobility. The relative proportion of each pathogen determines whether pain is wandering (Wind), severe and fixed (Cold), or with swelling and heaviness (Dampness).

Summer-Heat with Dampness (暑湿)

Combined with Summer-Heat as a pathogen

Summer-Heat commonly combines with Dampness due to humidity. Causes fever, heavy head, chest oppression, nausea, loose stools, and fatigue. The Dampness component makes it more lingering and harder to clear.

Differentiation from Similar Pathogens

Distinguishing the Six Excesses from each other and from internally generated pathogens is essential for proper treatment:

  • External vs. Internal pathogens: External Six Excesses typically have exterior symptoms (aversion to cold/wind, floating pulse) at onset, while internally generated 'Five Internal Excesses' (内生五邪) arise from organ dysfunction without exterior signs
  • Wind vs. other pathogens: Wind is characterized by rapid onset and changeable symptoms; other pathogens are more stable in their presentations
  • Cold vs. Dampness: Both are Yin pathogens, but Cold causes sharp pain and contraction while Dampness causes heaviness and swelling; Cold has clear discharges while Dampness is turbid
  • Dryness vs. Heat consuming fluids: Both cause dryness, but Heat will show more red tongue and rapid pulse; Dryness alone may not show Heat signs
  • Summer-Heat vs. Fire: Summer-Heat only occurs in summer and always has an external origin; Fire can occur any time and may be internally generated

Treatment Principles

Treatment of the Six Excesses follows the principle of addressing the specific pathogen while supporting the body's righteous Qi (正气):

  • Wind: Disperse Wind (祛风), release the exterior; use acrid herbs that open the pores and expel Wind
  • Cold: Warm and disperse Cold (温散寒邪); use warm acrid herbs to restore Yang and expel Cold
  • Summer-Heat: Clear Heat and benefit Qi (清暑益气); clear the Heat while replenishing depleted fluids and Qi
  • Dampness: Transform and drain Dampness (化湿利湿); use aromatic herbs to transform Dampness and diuretics to drain it
  • Dryness: Moisten Dryness and nourish Yin (润燥养阴); use moistening herbs that generate fluids
  • Fire/Heat: Clear Heat and drain Fire (清热泻火); use bitter cold herbs to clear excess Heat

The classical principle states: treat the exterior first when exterior symptoms are present, then address the interior. Combined pathogens require combined treatment approaches.

Representative Formulas

Gui Zhi Tang

Classic formula for Wind-Cold with sweating (Tai Yang exterior deficiency); harmonizes Ying and Wei to release the exterior

Ma Huang Tang

Powerful formula for Wind-Cold without sweating; strongly opens the pores and disperses Cold

Yin Qiao San

Primary formula for Wind-Heat invasion; uses acrid cool herbs to disperse Wind-Heat from the exterior

Xin Jia Xiang Ru Yin

Addresses Summer-Heat with exterior symptoms; releases the exterior while clearing Summer-Heat

Huo Xiang Zheng Qi San

Transforms Dampness and releases the exterior; excellent for external Wind-Cold with internal Dampness

Sang Xing Tang

Treats warm-Dryness attacking the Lungs; moistens Dryness while gently clearing Heat

Bai Hu Tang

Powerfully clears Qi-level Heat; the flagship formula for high fever from Heat pathogen in the Yang Ming stage

Representative Points

GB-20

Fengchi

Major point for expelling Wind from the head and neck; treats headache, stiff neck, and exterior Wind invasion
LI-4

Hegu

Command point for the face and head; releases the exterior, expels Wind, and clears Heat; paired with LU-7 for colds
LU-7

Lieque

Luo-connecting point of the Lung; disperses Lung Qi, expels exterior Wind-Cold, and opens the nose
DU-14

Dazhui

Meeting point of all Yang meridians; clears Heat, releases the exterior, and strengthens Wei Qi
LI-11

Quchi

Clears Heat from the Blood and Qi levels; cools Blood and treats skin conditions from Wind-Heat
ST-36

Zusanli

Tonifies Qi and supports the body's resistance; strengthens the Spleen to transform Dampness
SP-9

Yinlingquan

Primary point for resolving Dampness; benefits the Spleen and promotes urination to drain Dampness

Classical Sources

Huang Di Nei Jing Su Wen (黄帝内经素问)

Chapter 74 - Zhi Zhen Yao Da Lun (至真要大论)

夫百病之生也，皆生于风、寒、暑、湿、燥、火

All the hundred diseases arise from Wind, Cold, Summer-Heat, Dampness, Dryness, and Fire.

Huang Di Nei Jing Su Wen (黄帝内经素问)

Chapter 5 - Yin Yang Ying Xiang Da Lun (阴阳应象大论)

风胜则动，热胜则肿，燥胜则干，寒胜则浮，湿胜则濡泻

When Wind predominates there is movement; when Heat predominates there is swelling; when Dryness predominates there is desiccation; when Cold predominates there is floating (edema); when Dampness predominates there is watery diarrhea.

San Yin Ji Yi Bing Zheng Fang Lun (三因极一病证方论)

Volume 2

夫六淫者，寒暑燥湿风热是也。六淫，天之常气，冒之则先自经络流入

The Six Excesses are Cold, Summer-Heat, Dryness, Dampness, Wind, and Heat. The Six Excesses are the normal Qi of Heaven; when they transgress, they first enter through the channels and collaterals.

Zuo Zhuan (左传)

Zhao Gong First Year (昭公元年)

天有六气……淫生六疾

Heaven has six types of Qi... when they become excessive, they produce six kinds of disease.

Modern References

SEED: the six excesses (Liu Yin) evaluation and diagnosis scale

Chen et al. (2015)

Published in Chinese Medicine journal; developed a validated diagnostic scale for the Six Excesses based on Delphi method with 32 TCM experts

The Foundations of Chinese Medicine

Giovanni Maciocia (2015)

Comprehensive textbook with detailed chapters on each of the Six Excesses, their characteristics, and clinical presentations

Chinese Medical Herbology and Pharmacology

John Chen and Tina Chen (2004)

Reference text organizing herbs by their actions against pathogenic factors including the Six Excesses

The Concept of Wind in Traditional Chinese Medicine

Acar and Koybasi (2017)

Published in Journal of Integrative Medicine; explores Wind as part of the Six Evils framework in contemporary practice