On Zheng, Zheng, Zheng, and Zheng 正，症，証，癥
The following is a note that Dr. Hood wrote up for her students at NCNM, to bring some clarity to the confusion around the different concepts and terms for "disease," "pattern," "syndrome," and "symptom" in Chinese medicine from a classical perspective. Thank you for sharing, oh great Doctor Hood!
癥 (classical) or 症 (simplified ) zheng refers to signs and symptoms, i.e., what the patient feels to be abnormal and the indications of imbalance the doctor perceives during the course of applying the four diagnostic techniques to said patient. This forms the foundation for the analysis and determination of disease and includes such things as symptoms (e.g., headache, cough, chest stuffiness, etc.) as well as signs (white face, red tongue, wiry slippery pulse etc.).
This character is the same as the one that is used in 症瘕 zheng jia (abdominal masses, or "concretions and conglomerations" in Wiseman terms) but the tone here is first rather than fourth; a tone change like this is usually indicative that the character is used in a completely different sense.
證 (classical) or 证 (simplified) zheng refers to what I will translate here as "indicators," "manifestations," or"evidence" but which is more usually translated as patterns or syndromes. It refers to an individual's overall responses to an underlying pathomechanism at a given stage of a disease. These responses typically include elements of a constellation of patho-mechanistically related symptoms that reflect the same underlying etiology, pathodynamic, disease location, nature of the disease, and force of the disease.
病bing refers to disease. This is defined as the entire evolutionary process of a disease factor as it plays out in both the struggle between correct/upright/healthy qi and pathogenic factors, as well as the disregulation or disharmony between Yin/Yang. This process has distinct developmental patterns and concretely manifests in discrete symptoms and syndromes specific to each stage of a disease in development.
辯證 (classical) or 辨证 (simplified) bian zheng (a term specific to Chinese Medicine) refers to"discrimination of patterns" or more commonly "differentiation of syndromes." It is understood to be the comprehensive analysis of all material relevant to the problem/disease in question gathered together in order to determine what syndrome one is dealing with and from there to act as evidence in the support of the protocol devised to address the problem.
正氣 (classical) or 正气 (simplified) zheng qi is often translated as upright qi, but is also translated as "correct qi" and"healthy qi" (as a juxtaposition to pathogenic qi). The character 正zheng means "upright" (this may be as opposed to slanted, a possible understanding of what is normally translated as "evil") as well as "correct", "just," or even "positive." The first two meanings are the earliest.
In classical Chinese, there is a lot of symbolism hidden in characters and between characters with parts that are the same. This is far less true with simplified characters, where the symbolism in many characters has been completely abandoned for the convenience of writing fewer strokes. Practically speaking, this meant that the meanings of many characters were collapsed into one character or that the changes to a character use a simple sound aspect that has nothing to do with the original meaning. For example, the classical version of 症 zheng is written 癥zheng: in the process of simplification, the inner part of the character was swapped for 正zheng, which of course has the same pronunciation as the original character. The final set of characters that was simplified was actually withdrawn as it was determined that too many meanings in one character meant that written Chinese was becoming unintelligible. (I have heard many people say that the original purpose of simplification was not only the education of larger numbers of people in a shorter period of time but in fact the elimination of Chinese as a character-based language and its emergence as a phonetically-based one in line with Western languages.)