Cold and Heat

Cold and heat are the two principles used to differentiate the nature of a disease. According to the fifth chapter of Plain Questions ' . " Predominance of yang gives rise to heat, and predominance of yin gives rise to cold. " Cold and heat syndromes are concrete manifestations of excess and deficiency of yin - yang. Distinguishing between cold and heat syndromes is important for guiding treatment.

Cold syndromes - Pallor, aversion to cold, absence of thirst or drinking a little hot drinks, loose stools, clear urine increased in volume. Pale tongue with white and moist coating. Slow pulse.

Heat syndromes - Red complexion, fever, thirst with preference for cold drinks, constipation, deep - yellow and scanty urine. Red tongue with yellow and dry coating. Rapid pulse.

Cold syndromes and heat syndromes

Cold syndromes are pathological conditions resulted from exposure to exogenous pathogenic cold or from deficiency of yang in the interior of the body. Heat syndromes are pathological conditions caused by invasion of exogenous pathogenic heat or by deficiency of yin in the interior of the body.

Since cold and heat syndromes are opposite in nature, the symptoms and signs they manifest are entirely different. Cold syndromes are revealed by aversion to cold, preference for warmth, tastelessness in the mouth, absence of thirst, pallor, cold limbs, lying with the body curled up, loose stools, clear urine which is increased in volume, pale tongue, white and moist coating, slow or tense pulse. Heat syndromes manifest as fever, preference for coolness, thirst with preference for cold drinks, redness of face and eyes, irritability, restlessness, constipation, deep - yellow and scanty urine, red tongue with yellow and dry coating, and rapid pulse.

Deciding whether a syndrome is of heat or cold nature cannot be based on one clinical manifestation alone. The correct conclusion is reached after careful observation of all the clinical manifestations. Of these, the presence of cold, heat and thirst and the conditions of complexion, four limbs, defecation, urination, tongue coating and pulse are the most important. Table 12 explains the differentiation of cold and heat conditions of excess type in interior syndromes.

The relationship between cold and heat syndromes

Although cold syndromes and heat syndromes are opposite in nature, they have a close relationship. They can exist simultaneously, manifesting as complicated syndromes of cold and heat. In given conditions, they can also be transformed into each other, presenting either transformation of cold syndromes into heat, or of heat syndromes into cold. When the disease has developed to a very severe stage, syndromes of true heat and false cold or true cold and false heat may appear.

Complicated syndromes of cold and heat

The patient may have simultaneous signs of heat in the upper half of the body, and of cold in the lower half. The syndrome like this is known as " heat above with cold below. " This is one of the most frequently seen complicated syndromes of cold and heat. Clinically the " heat above " manifests as suffocation and heat sensation in the chest and a frequent desire to vomit, whilst the " cold below " presents abdominal pain which can be alleviated by warmth, and loose stools. The syndrome is often due to a complicated etiology involving both cold and heat. This leads to a pathological disharmony of yin and yang of various zang - fu organs, and manifests as excess of yang in the upper part of the body and excess of yin in the lower part. Other frequently seen complicated syndromes are cold on the exterior with heat in the interior, and heat on the exterior with cold in the interior.

Transformation of cold and heat syndromes

In transformation of a cold syndrome into heat, the cold syndrome occurs first and gradually changes into a heat syndrome. An example is exposure to exogenous pathogenic cold which may lead to an exterior cold syndrome and produce such symptoms and signs as fever, aversion to cold, general aching, no sweating, white tongue coating and superficial and tense pulse. If this pathogenic cold goes deep into the interior of the body and turns into heat, cold signs such as aversion to cold will subside, but fever persists and other heat signs such as irritability, thirst and yellow tongue coating will occur in succession. This indicates the transformation of exterior cold into interior heat. In transformation of a heat syndrome into cold, the heat syndrome occurs first and gradually changes into a cold syndrome. An example is abrupt appearance of cold limbs, pallor, and a deep and slow pulse in the patient with high fever, profuse sweating, thirst, irritability, and a surging and rapid pulse. These are the manifestations of the transformation of a heat syndrome into a cold one. The mutual transformation of cold and heat syndromes takes place in certain conditions, depending crucially on the relative strength of the pathogenic factor and antipathogenic qi. Generally speaking, transformation of cold into heat results from a strengthening of the antipathogenic qi and hyperactivity of yang qi. Constitutional deficiency of yang, or exhaustion of yang qi during the course of a disease, may lead to a failure of the antipathogenic qi in resisting the pathogenic factor, thus giving rise to transformation of a heat syndrome into a cold one.

True and false phenomena in cold and heat syndromes

True heat with false cold refers to a syndrome in which there is heat in the interior of the body and false cold on the exterior. The syndrome is manifested as cold limbs, but a burning sensation in the chest and abdomen ; no aversion to cold, but aversion to heat ; and a deep but forceful pulse. In addition, there is thirst with preference for cold drinks, irritability, dry throat, foul breath, scanty, deep - yellow urine, constipation and a deep red tongue with yellow dry coating. In this syndrome, excessive internal heat binders the yang qi from reaching the exterior. True cold with false heat refers to a syndrome in which there is real cold in the interior and false heat on the exterior. Clinical manifestations are feverishness of the body, flushed face, thirst and a superficial pulse. However, the patient wants to cover up the body in spite of the feverishness, wants to take warm drinks to relieve the thirst, and has a superficial and weak pulse. In addition, there are other cold signs such as clear urine, loose stools and a pale tongue with white coating. In this syndrome, excessive yin cold in the interior forces the yang qi to the exterior. It is clear that the appearance of a disease does not necessarily reflect its essential nature in these types of syndromes. Careful observation and analysis should be made, if the false and true phenomena are to be differentiated accurately. Attention should be paid to the following points : Whether the pulse is forceful or weak ; whether the tongue is pale or red ; whether the tongue coating is moist or dry ; whether there is thirst or not ; whether the patient likes cold drinks or hot drinks ; whether the chest and abdomen are warm or not ; whether the urine is clear or yellow ; and whether the patient wants to cover up the body or not.