Transcript cause of disease

Chapter 6 Cause of Disease
Lecturer: QU Hongyan
Brief introduction
The cause of disease, refers to the factors that
damage the relative equilibrium and result in disease.
The etiology, an important component of the
theoretical system of traditional Chinese medicine,
studies the concept of various pathogenic factors, their
formation, nature, pathogenic characteristics and the
clinical manifestations of the disease caused by them.
Exogenous
pathogenic
factors
Pathological
products
Pathogenic
factors
Endogenous
pathogenic
factors
others
Methods to seek the cause of
disease
A characteristic of
etiology in TCM
seeking the
cause by
syndrome
differentiation
TCM studies the cause of a disease,
by understanding objective conditions
that may become pathogenic factors
according to the manifestations of the
disease and through analysis of
symptoms and signs of disease to
infer its cause
Exogenous pathogenic factors
 Exogenous pathogenic factors---refer to the
pathogenic factors which originate from the
nature and invade the body from the body
surface, or through the mouth and nose,
causing exogenous disease.
Six excesses
Pestilential qi
Six excesses
Basic concept
Six qi： a collective term for six normal climate
changes in nature including wind, cold, summerheat, dampness, dryness and heat (fire).
Six excesses： a collective term for six exogenous
pathogens including pathogenic wind, pathogenic
cold, pathogenic summer-heat, pathogenic
dampness, pathogenic dryness and pathogenic
heat (fire).
 Under the following conditions, six qi will
turn into six excesses:
six qi changes sharply, which goes beyond the
normal adaptive ability ；
body resistance becomes weak due to deficiency of
healthy qi.
Climatic
changes
（six qi）
Fall
ill
Healthy
qi
Healthy
Six
excesses
Six
qi
Common pathogenic characteristics
of six excesses
 1．Exogenousness：the six excesses usually
invade the body through the body surface, the mouth
and nose.
 2．Seasonality ：diseases caused by the six
excesses are often characteristic of distinct seasonality.
In spring there are more
wind diseases; dryness
disease more in autumn
Common pathogenic characteristics
of six excesses
 3．Regionality ：Diseases caused by the six
excesses are often connected with the environments
and regions where people live and work.
 4．Combination ：each of the six excesses can
cause disease either alone or in combination with
another.
e.g. wind-heat cold
wind-cold-dampness
arthralgia
Common pathogenic characteristics
of six excesses
 5．Transformability ：Under certain conditions, the
natures of diseases caused by six excesses can
transform into one another.
e.g. Wind-cold syndrome
of exterior may turn into
interior heat syndrome.
Wind pathogen

All exogenous pathogenic factors
characteristic of lightness, rising, and
opening-dispersing and migrating are
called wind pathogen.
Natures and characteristics
 Wind pertains to yang and is characteristic of
lightness, rising and opening-dispersing and
tends to attack yang location
 Characteristic of wind being mobile and rapid
changeable
 Characteristic of wind being mobile
 Wind being primary pathogen
Cold pathogen

All exogenous pathogenic factors
characteristic of cold, coagulation and
contraction are called cold pathogen.
 Cold is prevalent in winter so there are
more diseases caused by cold in this
season. Diseases caused by cold can
also be seen in other seasons.
Natures and characteristics
 Cold pertains to yin and is apt to attack yang
qi
 Cold having property of coagulation and
stagnation
 Cold having property of contraction
Dampness pathogen
All exogenous pathogenic factors
characteristic of heavy turbidity, stickiness and
stagnation and downward are called dampness
pathogen.
 Dampness is the dominant qi in late-summer or
in the intersection of summer and autumn, it is
the dampest in the year because there is
steaming damp-heat and vaporizing water.
 In addition, diseases caused by dampness can
also result from swimming and drenching, living
in wet and damp places and working in the water.
Natures and characteristics
 Dampness is a yin pathogen and apt to
hamper qi movement and damage yang qi
 Characteristic of dampness being heavy and
turbid
 Characteristic of dampness being sticky and
stagnant
 Characteristic of dampness being
descending and apt to attack yin locations
Summer-heat pathogen
During the time from summer solstice to
autumn begins, the exogenous pathogenic
factors characteristic of scorching-hot,
ascending and dispersive, mixed with dampness
are called pathogenic summer-heat.
 Summer-heat is the dominant qi in summer and
transformed from fire-heat qi. It is only seen in
summer, which is characterized by an apparent
seasonality. So summer-heat is a pure
exogenous evil and attacks the body usually not
from the interior, but the exterior.
Natures and characteristics
 Summer-heat pertains to yang and is
characteristic of scorching-hot
 Characteristic of summer-heat being
ascending and dispersive, impairment of
fluids and exhaustion of qi
 Summer-heat being likely to be mixed with
dampness
Dryness pathogen
All exogenous pathogenic factors
characteristic of dryness and astringency
are called dryness pathogen.

Dryness, the dominant qi in autumn
marked by depurating, descending,
astringency and dryness, can be seen in
four seasons of the year.
Natures and characteristics
 Characteristic of dryness being dry and
puckery and apt to impair fluids
 Dryness likely to injure lung
The lung is a tender viscus. It
is externally connected with
skin and hair, opens into the
nose and aversion to dryness
Fire (heat) pathogen
All exogenous pathogenic factors characteristic
of torridity and flaming up are called fire (heat)
pathogen.
 Fire (heat) blooms in summer but is not so
seasonal as summer-heat and it is no affected
by seasons and climates. therefore fire diseases
are seen in four seasons.
Natures and characteristics
 Fire (heat) is a yang pathogen which
characteristic being flaring up
 Fire (heat) being likely to disturb heart-mind
 Fire (heat) being likely to consume body fluids
and exhaust qi
 Fire (heat) being likely to cause convulsion and
bleeding
 Fire (heat) being likely to cause sores and
abscesses
Pestilential qi
Concept
 It is an exogenous pathogenic factor which is strongly
infective, and it can cause diseases through air, food,
bites by insects and animals, dermal contact, etc.
Pathogenic characteristics of pestilential qi
 Strong infective and epidemic
 Acute onset and severe condition
 Diseases vary with pestilential qi but symptoms are
similar
Internal injury pathogenic factors
 Internal injury cause of disease are those generated
internally, which can directly lead to disorders of qi
and blood as well as impairment of visecra.
Internal injury due to seven emotions
Improper diet
Overstrain and overease
Internal injury due to seven emotions
Basic concept
Seven emotions： refer to seven emotional
activities including joy, anger, worry, anxiety,
sadness, fear and fright.
Internal injury due to seven emotions
：when
the emotional stimulations are too abrupt, violent,
and prolonged and beyond one’s adaptability or
when there is diminished adaptability due to
imbalanced yin-yang, qi and blood of viscera, can
they turn into pathogenic factors.
Fall
ill
Emotional
stimulus
Healthy
qi
Be
healthy
Internal
Injury due
To seven
emotions
Seven
emotions
Relationship between seven emotions and
visceral essential qi
五脏
liver
heart
spleen
lung
kidney
store
transform
essence
impair
generate
Qi
hurt
injure
情志
anger
joy
anxiety
sadness
fear
Pathogenic characteristics




Impairing the viscera
Affecting the visceral qi movement
Tending to cause emotional diseases
Affecting the sequelae of diseases
Rage leading to qi ascending,
excessive joy leading to qi loose
Fear leading to qi sinking
Fright leading to qi turbulance.
Irregularity of diet
Improper diet
Unhygienic diet
Food preference
Improper diet
Conscious control
of eating
Overeating impairs
the spleen and
stomach
Obstinate
Psychological
diseases
Anorexia, lusterless
Complexion, palpitations
Short breath, general
lassitude
Gastric and abdominal
fullness and distention
eruction, acid regurgitation
anorexia, vomiting
and diarrhea
Unhygienic diet
 This refers to eating unclean food, such as taking food
gone bad, polluted by pestilent evils, parasites or
mistaken intake of poisonous food.
Take in the food
that has gone
bad
Take in the food
contaminated
by epidemic toxin
Gastric and abdominal
pain, nausea and
vomiting, diarrhea with
borborygmus,
or dysentery
Infectious
diseases
Diet predilection
 This refers to the phenomenon that diseases can start
due to the liking of foods with certain taste or specially
eating certain foods, including predilection for cold or hot
food, or predilection for one of the five tastes or
predilection for alcohol.
Predilection for
cold or heat
Predilection for
the five tastes
Predilection
for alcohol
Predilection for
one type of
food
Predilection for cold or heat
Excessive intake
of cold food
Impair the yang
qi of spleen
and stomach
Cold-dampness
is produced
internally
Abdominal pain
diarrhea
Partiality to
spicy-hot food
Impair the
stomach yin
Thirst, halitosis,
abdominal distention
pain, constipation
etc
Predilection for the five tastes
Long term of preferring food with a certain taste
can cause the preponderance of its corresponding
viscera, thus causing disharmony among viscera.
e.g.
acid
bitter
sweet
pungent
salt
liver
heart
spleen
lung
kidney
Predilection for one type of food
 It refers to a long period of special taking of some foods
or not taking some foods or lack of certain food.
Long time of
excessive ingesting
rich food
Long time for lacking
of some nutrients
Production of
Phlegm and
transformation
of heat
Night blindness
goiter and tumor
Obesity, vertigo
stroke, consumptive
thirst and so on
Imbalance between work and rest
Imbalance between work and rest
It refers to long time of overstrain or indulgence
in easy life.
Normal work can help build the body and improve health
Proper rest can remove fatigue and help recover strength
overexcertion
overstrain
Mental
overstrains
Sexual
overstrains
Overease/ indulgence in easy life
Overexertion
It refers to prolonged engagement of physical labor or
exercise, beyond a normal limit.
Consumption of qi
Impairment of the body
Impair the functions
of viscera and cause
asthenia of visceral qi
Injure muscles,
tendons and bones
Reluctant to speak
fatigue and tiredness
sweating, dyspnea
etc
Mental overstrains
It refers to long time of attention or pensiveness.
mental
overstrains
Impair the heart
and the spleen
and consume qi
and blood
Heart throb, amnesia, insomnia
dreaminess, poor appetite,
abdominal distention and
diarrhea, etc.
Sexual overstrains
It refers to excessive sexual activities, masturbation,
or early pregnancy or giving many births.
sexual
overstrains
Consume essence
In the kidney
Aching and weakness in the
waistand knees, vertigo, tinnitus,
dispiritedness, or spermatorrhea
prospermia, and impotence
in men and dysmenorrhea
leukorrhea or sterility
in women
Indulgence in easy life
Absence of
physical work
sports
Qi stagnation of
the spleen and
stomach
Reduced appetite, abdominal
distention, limb heaviness,
muscular flaccidity, oppression
in chest and shortness
of breath
Pathological products
 Phlegm-fluid retention
 Stagnant blood
 calculus