Apart from the principle of medical treatment which consists in the saying "If the disease is acute, treat what is on the surface; if the disease is slow-going, treat what is at the root," traditional Chinese medicine also adopt methods of concurrent treatment in certain circumstances. In other words, what is on the surface and what is at the root are attended to simultaneously ---in instances when both are important. For example, if a patient who has got flu is very weak, consideration should be given to his/her weak constitution as well as the fact that he/she has got the flu. In such a case,medical treatment is necessary to go along both lines, to tackle simultaneously what is on the surface and what is at the root, so that health may be enhanced through the use of tonics. The flu may be likened to an evil spirit. After the evil spirit has been exorcised, the body will become stronger and it will be benefited by the tonics. This is an illustration of the typical method of concurrent treatment of what is on the surface and what is at the root.
In the theory of traditional Chinese medicine there is another important medical treatment principle, which is worded as "in order to cure a disease seek for what is at its root." The implication is that for the purpose of curing a certain disease one must lay hold of the essence of the disease and take measures of treatment targeted at the essence. One must never overlook what is at the root of the disease when one is trying to do away with some symptom which, in regard to that disease, is presumably not at its root but on its surface. One should by all means avoid confining one"s attention to that part of the body some ache of which is being complained of. In complicated diseases symptoms which are intricate and bewildering are often encountered, and many symptoms are continually changing with the progress of the course of the disease. If one should attempt to eliminate all these symptoms one by one as they occur, there would be too much work to do, and it is likely that one"s efforts would be to no avail. The patient"s illness would, in all probability, even get more and more serious. This is due to the error of failing to "seek for what is at the root of the disease".