| The subject of aetiology is the study of the causative factors of disease shile the study of pathogenesis concerns the actual bodily processes whereby disease occurs, develops and, changes.|
Numerous factors can cause disease and, these include the six exogenic factors, the seven emotions, improper diet, over strain, lack of physical exercise, traumatic injuries, bites by insects or animals, as well as stagnant blood and phlegm fluid. The symptoms and signs of any disease reflect the pathological reaction of the body to certain causative factors. The causative factors therefore, are studied both as the objective causes of disease and, in the specific ways they affect the body. On the basis of this understanding, traditional Chinese medicine is able to identify the causative factors of disease by analyzing the clinical manifestations. This is know as 'seeking the causative factors by differentiating symptoms and signs. The study of aetiology therefore, is based on developing a propound understanding of the characteristic clinical manifestiations produced by each causative factor.
1)The Six Exogenous Factors
(1) Wind: Wind is the predominant Qi of spring but, may also occur in any of the four seasons. Wind may easily invade the body after sweating or whilst sleeping.
a. Wind is the primaryexogenous pathogenic factor in causing disease since, cold, damp, dryness and, heat all depend on wind to invade the body.
Pathogenic wind cannot only combine with the other five exogenous factors but, also with phlegm. Facial paralysis for example, is mostly seen as a consequence of the obstruction of wind phlegm in the meridians.
b. wind is a yang pathogenic factor and is characterized by 'upward and outward dispersion', it can therefore easily invade the upper body of the body i.e. the head, face and, the exterior portion of the body, leading to impairment of the opening and closing of the pores. clinical manifestations are headache, nasal obstruction, itching, or pain in the throat, facial puffiness is an aversion to wind and sweating.
c. Wind in nature blows in gusts and is characterized by rapid changes. Disorders caused by pathogenic wind therefore, are marked by migratory symptoms rapid changes and abrupt onset of disease. The migratory joint pain of wandering 'bi' syndrome. Uticaria caused by pathogenic by wind is characterized by itching of the skin and wheals which appear and disappearfrom place to place.
d. Wind is characterized by constant movement. Moving pathogenic wind in the body can cause dizziness, vertigo, fremitus, convulsions and opistotonos.
(2) Cold : cold is the predominant Qi of water, may occur in other seasons but, not as severly. Thin clothing, exposure to cold after sweating, being caught in rain and, wading in water in cold winter can give rise to invasion of pathogenic cold.
a. Cold is a yin pathogenic factor which consumes the yang Qi of the body, as a result the warming function of the body will be impaired, resulting in symptoms such as cold limbs, cold pain in the epigastric and abdominal regions, diarrhea containing undigested food, increased flow of clear urine, etc.
b. Cold is characterized by contraction and stagnation, resulting in impairment of the opening and closing of the pores, spasmotic contraction of the tendons and meridians and, impaired circulation of Qi and blood. Acompanying symptoms include pain, aversion to cold, lack of sweating and restricted movement of the limbs.
(3) Summer heat : Summer Heat is the predominant Qi of summer and, unlike the other exogenous factor, is only seen in its own season. Summer heat diseases are induced by excessively high tempertures, over exposure to the blazing sun whilst working, not working, or staying for too long in poorly ventilated places.
a. Summer heat : is characterized by extreme heat, is a yang pathogenic factor whichis transformed from fire. Clinical manifestations characterized by yang heat including high fever, restless, thirst, profuse sweating and a surging pulse.
b. Summer heat is characterized by upward direction, dispersion and, consumption of body fluid. It usually affects the head and eyes causing, dizziness and blurred vision. Due to its dispersing function, pathogenic summer heat may cause the pores to stay open, the excessive sweating sweating that may consume body fluid resulting in thirst with a strong desire to drink, dry mouth and tongue, scanty deep-yellow urine. In addition, such as reluctance to speak and the less it is used. Severe invasion of summer heat may disturb the mind, resulting in sun stroke with the syndromes of sudden collapse and coma.
c. Since summer is often characterized by high humidity, pathogenic summer heat is frequently combined with pathogenic damp. Clinical manifestations of summer heat and damp include dizziness, heaviness in the head, suffocating sensation in the chest, nausia, poor appetite, loose stools and, general lassitude, fever, restlessness, thirst.
(4)Damp : damp is the predominant Qi of late summer - the period between summer and autumn which in China is a hot, rainy season with abundant damp everywhere. many diseases related to invasion by pathogenic damp occur at this time. Damp diseases may also be induced by living in damp conditions and places, wearing clothes made by damp by sweat or rain, frequent exposure to water and, periods of prolonged rain.
a. Damp is characterized by heaviness and turbidity. Patients often complain of dizziness, a heaviness sensation in the head as though it were carrying a heavy load and, soreness, pain and, heavy sensation in the joints. There may be turbid discharges from the body, such as suppurating sores, weeping eczema profuse purulent leukorrhea with a foul odor, turbid urine and stools containing mucus and even blood.
b. Damp is characterized by viscosity and stagnation. Patients affexted by pathogenic damp usually have a stubborn sticky tongue coating, a viscous stool that is difficult to excrete and, obstructed urination. Diseases due to pathogenic damp tend to be prolonged and interactable, such as fixed by 'bi' syndrome, damp fever(intestinal typoid) and eczema.
c. damp is a yin pathogenic factor which impaires yang and easily obstructs Qi circulation. Clinical manifestations include a full sensation in the chest, epigastric distention, difficult and scanty urination and hesitant bowel movements with viscous stools, since the spleen 'likes dryness and dislikes damp' pathogenic damp is likely to impair spleen yang, leading to distention and fullness in the epigastrium and abdominum, poor appetite loose stools, reduced urination and oedema, sue to poor transportation and transformation and inadequate dispersion of body fluids.
(5) Dryness : Dryness is the predominant Qi of autumn and, it often occurs in China which is usually very dry.
a. Dryness consumes body fluid resulting in dryness of the nose and throat, withered body hair, constipation and reduced urination.
b. pathogenic dryness often impaires the function of the lung, the 'delicate' zang, which has the function of dispersing, descending and moistening. Dryness invades the lung through the nose or mouth. When lack of moisture impaires the dispersing and descending functions of the lung, there maybe adry cough with scanty sticky or blood sputum.
(6) Fire (warmth and heat) : Fire, caused by excess of yang Qi, often occurs in summer but, maybe seen in other seasons. Fire, warmth and ehat vary in degree of the three. Fire is the most severe and warmth the least severe yet, they all share similar characteristics, the terms of fire heat and warm heat therefore, are often used to describe their common features.
a. Fire is a yang pathogenic factor characterized by burning and upward direction. Clinical manifestations include high fever, restlessnessm thirst, swelling, mouth and tongue ulcer, swollen and painful gums, headache and congestion of the eyes, restlessness, insomnia, mania, emotional excitement and coma or delirium may occur if pathogenic fire disturbs the mind.
b. pathogenic fire often consumes yin fluid. Burning pathogenic fire heat can consume yin fluid and force it to the exterior of the body fluid. clinically, apart from high fever, there may be thirst with desire to drink, dry lips and throat, constipation and deep-yellow scanty urine.
c. Invasion by fire stires up wind and causes disturbance of blood, excess of fire heat affects the liver meridian and deprives the tendons and meridian of nourishment thus, stirring up the liver wind. Clinical manifestiations include high fever, coma, convulsion of the four limbs, neck ridgidity, opisthotonos and upward starring of the eyes. These symptoms are known as 'extreme heat stirring up wind'.
2) The Seven Emotional Factors
The seven emotional factors in traditional chinese medicine are joy, anger, melancholy, worry, grief, fear and, fright. These are normal emotional responses of the body to external stimuli and, do not normally cause disease. Severe continous or abruptly occuring emotional stimuli however, which surpass the regulative adaptability of the organism will affect the physiological functions of the human body especially, when there is a pre-existing over sensitivity to them. The Qi and blood of the zangfu organs will be disrupted leading to disease. The seven emotional factors, differing from the six exogenous factors directly affect the zang fu organs, Qi and, blood. They are considered to be the main causative factors of endogenous diseases.
||Qi to rise up
||Move Qi slow
||To be derranged
3) Improper diet, overstrain, stress and, lack of physical exercise
4) Traumatic injury and insect or animal bite
5) Phlegm fluid and stagnation blood
1. Disharmony of yin and yang
2. Conflict between antipathogenic Qi and pathogenic Qi
3. Abnormal ascending or decending of Qi