---
title: "Causes of disease"
url: "https://acuiq.com/wiki/theory/causes-of-disease"
updated: 2026-10-10
last_verified: 2026-10-10
license: CC-BY-4.0
license_url: "https://creativecommons.org/licenses/by/4.0/"
section: "theory"
basis: "Classical"
audience: "Anyone"
published: "2026-10-09"
reading_minutes: 7
sources: 5
---

# Causes of disease

_The three categories Chinese medicine sorts causes into – the six excesses, the seven emotions, and the causes that are neither – as the WHO terminologies define them._

In Chinese medicine the cause of a disease is part of the diagnosis. The WHO’s [2007 standard terminology for the Western Pacific](https://iris.who.int/handle/10665/206952) defines pattern identification as determining the location, cause and nature of a patient’s disease, and the WHO’s [2022 terminology for traditional Chinese medicine](https://iris.who.int/handle/10665/352306) has a term for working back from the presentation to the cause: differentiating the pattern to reveal the aetiology, which it defines as seeking the causative factors according to the clinical manifestations. The causes are therefore read from what the [four examinations](/wiki/theory/the-four-examinations) find. They are sorted into three categories, and this page sets out each one as the two WHO terminologies define it.

## Three categories of cause

The 2007 terminology calls the three causes an ancient classification of causes of disease. The 2022 edition names it the theory of three aetiological categories and defines the three as follows.

| Category | Chinese | What it mainly refers to |
| --- | --- | --- |
| External causes | wai suo yin | The six exogenous pathogenic factors |
| Internal causes | nei suo yin | The seven emotional disturbances |
| Neither internal nor external | bu nei wai yin | Improper diet, over-exertion, traumatic injuries, animal and insect bites, drowning and the like |

The scheme is associated with Chen Yan (1121–1190), a Song dynasty physician whose courtesy name was Wuze. A [profile on the Lishui government’s English site, presented by China Daily](http://zhejiang.chinadaily.com.cn/lishui/2019-11/28/c_427232.htm), Lishui being his home city in Zhejiang, describes his book as 18 rolls of nearly 240,000 words, divided into 180 categories and recording more than 1,050 prescriptions. The [National Palace Museum in Taipei](http://theme.npm.edu.tw/exh108/HealthandLongevity/en/page-4.html) renders its title, Sanyin jiyi bingzheng fanglun, as Treatise on the Three Categories of Pathogenic Factors. A doctoral project at the [University of Oslo](https://www.hf.uio.no/ikos/english/research/news-and-events/events/phd/2024/phd-midterm-minh-khai), which translates the title as A Unified Treatise on Diseases, Patterns, and Recipes According to the Three Causes, is tracing the sources of Chen’s doctrines of the seven affects and the three causes.

## The six excesses

The 2007 terminology defines the six excesses as the six excessive or untimely climatic influences acting as external pathogenic factors: wind, cold, summer heat, dampness, dryness and fire. Each is defined by how it behaves.

| Excess | Characterised by |
| --- | --- |
| Wind | Opening the pores, high mobility, upward and outward movement; called the leading cause of disease because it combines with cold, dampness, dryness and heat |
| Cold | Coldness, stagnation, congealing and contraction; impairs yang qi and blocks the channels, causing pain |
| Summer heat | Seen between the summer solstice and the beginning of autumn; extreme heat that ascends and disperses, often mixed with dampness |
| Dampness | Heaviness, turbidity, stickiness and downward flow; obstructs the movement of qi |
| Dryness | Consumes body fluids; enters through the nose, mouth and pores and damages the lung |
| Fire | Flames upward, consumes qi and fluids, engenders wind, stirs the blood and disturbs the heart spirit |

The excesses combine. The 2007 terminology defines wind-cold, wind-heat, wind-dampness, cold-dampness, wind-cold-dampness and dampness-heat as combined pathogens, and summer heat with dampness as another. It also defines an internal counterpart for four of them, internal wind, cold, dampness and dryness, so the same word can name a climatic exposure or a condition arising inside the body. Both terminologies place one external cause outside the six: pestilence, which the 2022 edition calls pestilence qi and defines as exogenous pathogenic factors with high contagiousness. Several of these terms are in AcuiQ’s index because published sources used them, among them [wind](/symptoms/wind), [wind exterior](/symptoms/wind-exterior), [damp](/symptoms/damp) and [heat](/symptoms/heat). [Patterns, symptoms and what you can look up](/wiki/theory/patterns-and-symptoms) explains why a term of this kind sits in a symptom index.

## The seven emotions

The 2022 terminology lists the seven emotions as joy, anger, anxiety, overthinking, grief, fear and fright. It treats them as normal, and uses a separate term, seven emotions causing internal damage, for the harm done when they are extreme. The 2007 edition says the same thing in one definition: the seven are endogenous causes of disease if in excess. It also has a shorter list, the five minds, of joy, anger, thought, anxiety and fear. The 2022 edition pairs five of the emotions with an organ each, and the 2007 edition gives an effect for all seven.

| Emotion | Organ affected | Effect described |
| --- | --- | --- |
| Anger | Liver | Liver qi rises, disordering qi and blood (2022); headache, flushed face, bloodshot eyes (2007) |
| Joy | Heart | Consumes heart qi and damages the heart spirit (2022); absentmindedness, palpitations, insomnia (2007) |
| Overthinking | Spleen | Spleen qi stagnates, impairing transportation and transformation (2022) |
| Grief | Lung | Consumes lung qi (2022); shortness of breath, listlessness, fatigue (2007, under the term sorrow) |
| Fear | Kidney | Kidney qi descends, impairing the storing of essence (2022); incontinence or fainting (2007) |
| Anxiety | Lung | Damages the lung, and with thought may injure the spleen (2007) |
| Fright | Heart | Occurs suddenly and disturbs heart qi, causing palpitations or confusion (2007) |

The organs named are the zang-fu of Chinese medicine, and The zang-fu organs covers how they differ from the anatomical organs of the same names. The 2022 terminology adds that five of the emotions can transform into fire, giving a fire pattern. [Anger](/symptoms/anger) is one of the emotion terms in AcuiQ’s index.

## Neither internal nor external

The third category collects causes that are neither climatic nor emotional. The 2022 terminology groups most of them under diet and under an imbalance of work and rest:

- **Diet.** Dietary irregularities, meaning excessive hunger and binge eating; contaminated or poisonous food; and predilections for particular food, including cold or hot food, certain flavours and alcohol. A habitual preference for one of the five flavours, spicy, sweet, sour, bitter or salty, is held to damage the five zang organs.
- **Overwork and inactivity.** Overwork, which the 2022 edition says can be physical, mental or sexual: physical overwork causes qi deficiency, mental overwork damages heart blood and spleen qi, and sexual overindulgence consumes kidney essence. Physical inactivity is listed as a cause in its own right. The five exhaustions name five prolonged activities: long looking damages the blood, long lying the qi, long sitting the muscles, long standing the bones, and long walking the sinews.
- **Injury.** Traumatic injuries, animal and insect bites, and drowning.
- **Treatment.** The 2022 terminology also defines medical malpractice as a cause: errors by health care professionals that induce or aggravate a condition.

Parasites appear in the 2022 terminology as one of the contributing factors in its definition of an excess pattern, and the 2007 edition defines a parasitic toxin. The 2007 edition also defines failure to acclimatise to a new environment. Both editions recognise inherited causes: the 2007 edition names constitutional insufficiency, and the 2022 edition defines maternal-to-fetal transmission and congenital weakness.

## Products that become causes

Some causes are produced by the body itself. The 2022 terminology defines phlegm as a viscous, turbid product of disordered water metabolism that can be a cause of many diseases, static blood as a product formed when blood flows slowly or coagulates, and stones as gravel-like accumulations in the ducts and cavities of the organs, and it calls the last two secondary pathogenic factors. Retained fluids are defined alongside phlegm. These terms reach AcuiQ’s index too, as [phlegm](/symptoms/phlegm) and [blood stasis](/symptoms/blood-stasis).

## What the classification can and cannot tell you

The WHO terminologies define how the causes are named and what each is held to do. The 2022 edition gives its purpose as letting professionals, policy-makers and the public use the same concepts and definitions in health care, medical records and training. It does not test the scheme. Because a cause is read from the clinical manifestations rather than observed, “wind” in a diagnosis records a practitioner’s conclusion about the presentation, not a measured exposure to weather. How often practitioners reach the same conclusion from the same patient is reported in [The four examinations](/wiki/theory/the-four-examinations). AcuiQ records a cause term wherever a published prescription or a point’s indication list used one, and cannot say whether the patients in a study would have been given the same cause by another practitioner.

### Sources

1. WHO Regional Office for the Western Pacific, WHO international standard terminologies on traditional medicine in the Western Pacific Region, 2007 — https://iris.who.int/handle/10665/206952
2. World Health Organization, WHO international standard terminologies on traditional Chinese medicine, 2022 — https://iris.who.int/handle/10665/352306
3. Lishui Municipal People's Government and China Daily, Chen Yan (profile), 2019 — http://zhejiang.chinadaily.com.cn/lishui/2019-11/28/c_427232.htm
4. National Palace Museum, Taipei, Health and longevity exhibition: causes of illness — http://theme.npm.edu.tw/exh108/HealthandLongevity/en/page-4.html
5. University of Oslo, Department of Culture Studies and Oriental Languages, PhD midterm evaluation: Minh Khai, on Chen Wuze's seven affects doctrine, 2024 — https://www.hf.uio.no/ikos/english/research/news-and-events/events/phd/2024/phd-midterm-minh-khai