This issue covers:
1.Deficiency and Excess
2.Changes in Deficiency and Excess
3.Pathological Phenomena of Deficiency and Excess
4.True Excess and False Deficiency, True Deficiency and False Excess
1.Deficiency and Excess
Deficiency and excess represent the state of the disease process regarding the rise and fall of pathogenic and righteous qi. Determining deficiency and excess is to assess whether the primary contradiction in the diseased body lies in the pathogenic aspect or the righteous aspect.
Excess refers to a pathological state of excessive pathogenic qi, while deficiency refers to a pathological state of insufficient righteous qi. The Suwen (Plain Questions) states: “When pathogenic qi is strong, it is excess; when essence and qi are depleted, it is deficiency.”
Many TCM theoretical texts consider deficiency and excess as a comparison of the strengths of pathogenic and righteous qi. Zou Shizhen believes that deficiency and excess do not describe the comparison of pathogenic and righteous qi, but rather describe the respective conditions of the body’s pathogenic and righteous qi.
As long as pathogenic qi exists in the body, it is considered excess; if the essence, qi, blood, and organs are below normal levels, it is considered deficiency; when both exist in the body, it is termed mixed deficiency and excess.
2.Changes in Deficiency and Excess
During the occurrence and development of a disease, with the rise and fall of pathogenic and righteous qi, deficiency and excess can change. When pathogenic qi harms righteous qi, it leads from excess to deficiency; when righteous qi is deficient and pathogenic qi accumulates, it leads from deficiency to excess.
3.Pathological Phenomena of Deficiency and Excess
The pathological phenomena exhibited by excess are related to the nature, quantity, and location of the pathogenic qi. For example, when cold pathogenic qi invades the Taiyang (Greater Yang), it causes fever, body aches, and a tight, forceful pulse; when heat pathogenic qi invades the Yangming (Bright Yang), it presents with high fever, agitation, loud voice, abdominal pain with resistance to pressure, constipation, a forceful pulse, and a yellow, dry tongue coating.
The pathological phenomena exhibited by deficiency are related to the components, locations, and degrees of deficiency. For instance, lung qi deficiency presents with fatigue, pallor, shortness of breath, spontaneous sweating, and a weak pulse; kidney yin deficiency presents with night sweats, five-center heat, thirst, and a thin, rapid pulse.
4.True Excess and False Deficiency, True Deficiency and False Excess
Some patients may exhibit pathological phenomena that are contrary to their deficiency and excess constitution, termed true excess and false deficiency or true deficiency and false excess, which require special attention for differentiation in clinical practice.
True Excess and False Deficiency
This refers to a state of excessive pathogenic qi, but the pathogenic qi is trapped within the body, obstructing the flow of qi and blood, leading to various manifestations of weak righteous qi, known as “great excess with signs of deficiency.”
For example, in cases of heat accumulation in the stomach and intestines, with internal heat blazing, due to yang qi being trapped internally and unable to disperse, the patient may present with a pale complexion, cold extremities, and a weak spirit, resembling false cold deficiency; however, these patients will also exhibit signs of internal heat such as constipation, abdominal pain with resistance to pressure, or hot, foul breath, with a pulse that is deep and thin but forceful upon heavy pressure.
True Deficiency and False Excess
This refers to a state of weak righteous qi, where the body is easily influenced by external factors, leading to pathological phenomena of excess without the presence of pathogenic qi.
For instance, in cases of spleen qi deficiency, where the transformation and transportation are weak, the patient may experience abdominal distension and pain upon eating, resembling signs of excess due to food stagnation; however, these symptoms may vary in intensity, with the patient preferring pressure and massage, and lacking the common pathological signs of food stagnation such as foul breath and a thick, greasy tongue coating.
Additionally, a patient with qi deficiency may exhibit high fever with only slight exertion, but without exposure to heat pathogenic qi, nor is it due to excessive resistance to cold pathogenic qi; although there is high fever, there is no thirst, and the pulse may be rapid but weak.