Zhang Jiebin stated: Hebing (Concurrent Disease) refers to the simultaneous onset of pathologies in two or three Yang meridians, representing a merging of diseases. Bingbing (Sequential Disease) occurs when, for example, the Taiyang meridian is initially affected and the pathology remains unresolved, subsequently spreading to the Yangming or Shaoyang meridians. As Zhang Zhongjing noted: "In Bingbing of two Yang meridians, when the Taiyang disease is first contracted, diaphoresis is applied. If the sweating is incomplete, the pathology transfers to the Yangming." If the symptoms of the Taiyang meridian have not ceased, purgation should not be used. The phrase "transfers to Yangming" indicates the origin from Taiyang; stating that "Taiyang symptoms persist" confirms that both meridians are involved.

Generally, Bingbing progresses from superficial to deep, transmitting from one meridian to another, which is an inevitable trend of disease progression. This defines the meaning of Hebing and Bingbing. Those who do not understand this may consider it a rare condition, yet they fail to realize that contemporary diseases are predominantly Hebing and Bingbing. Since I began clinical practice, I have never encountered cases where transmission follows a single meridian sequentially, nor have I seen cases where exterior symptoms completely resolve leaving only interior symptoms. If one seeks symptoms strictly according to classical textual patterns, such precise presentations are rarely found, nor are there formulas that perfectly match them. This stems from a lack of understanding of Hebing and Bingbing. The following outlines the general principles:

Hebing refers to the simultaneous involvement of two or three meridians. For instance, initial fever, aversion to cold, and headache are symptoms of the Taiyang meridian; if accompanied by insomnia, it constitutes Hebing of the Taiyang and Yangming meridians. If accompanied by vomiting and nausea, it is Hebing of the Taiyang and Shaoyang meridians. If fever, insomnia, vomiting, and nausea all present, it is Hebing of the Yangming and Shaoyang meridians. If all three sets of symptoms are present, it is Hebing of the Three Yang meridians, indicating severe pathology. There is no concept of Hebing between the Three Yang and Three Yin meridians because the Three Yang govern the exterior and the Three Yin govern the interior. Simultaneous involvement of exterior and interior is termed Lianggan (Double Strike). Therefore, when both Yin and Yang meridians are affected, it inevitably progresses through gradual transmission, classifying it as Bingbing rather than Hebing or Lianggan.

The distinction lies in timing: Hebing implies simultaneous onset, whereas Bingbing implies sequential transmission from one meridian to others. For example, if Taiyang disease presents with fever and headache, followed later by eye pain, nasal dryness, and insomnia, this is Taiyang Bingbing into Yangming. If followed by deafness, hypochondriac pain, vomiting, and bitter taste, it is Taiyang Bingbing into Shaoyang. If followed by abdominal fullness and dry throat, it is Taiyang Bingbing into Taiyin. If followed by dry tongue and mouth, it is Taiyang Bingbing into Shaoyin. If followed by irritability, abdominal fullness, and retraction of the genitals, it is Taiyang Bingbing into Jueyin. If Yangming transmits to the Three Yin, nasal dryness and insomnia will coexist with Yin symptoms. If Shaoyang transmits to the Three Yin, deafness, vomiting, and bitter taste will coexist with Yin symptoms. Although Yin pathology manifests internally, Yang symptoms remain on the exterior, hence termed Bingbing.

In Shanghan (Cold Damage) cases where fever persists throughout, it indicates that exterior pathogens have not been resolved. Once proper sweating occurs, both exterior and interior conditions heal. Is this not a case of Yin-Yang Bingbing? Contemporary Shanghan cases are mostly Bingbing; understanding this principle provides clarity. Treatment for Bingbing involving the Three Yang meridians requires resolving the exterior of these meridians. Pathogens in Taiyang are considered the exterior of Yang; treatment should use light and clear methods. Pathogens in Yangming are the interior of Yang; treatment should use heavy and concentrated methods. Pathogens in Shaoyang are the pivot of Yang; treatment should employ harmonizing methods. These are exterior-resolving strategies.

For pathology entering the Three Yin meridians, which are interior: Taiyin is Yin within Yang; treatment uses mild warming. Shaoyin is the pivot of Yin; treatment uses semi-warming. Jueyin is Yin within Yin; treatment uses strong warming. These are general principles for treating Yin diseases. However, even when pathology is in the Yin meridians, concurrent Bingbing with the Three Yang may occur. If heat pathogens are intense, clearing fire is appropriate. If exterior pathogens remain unresolved, dispersing them is necessary. Since pathogens enter from outside, the exterior is the root; removing the root ensures internal recovery. Thus, resolving the exterior can harmonize the middle. Conversely, if exterior pathogens are mild but interior symptoms are urgent, one must prioritize rescuing the interior. Exterior and interior Qi are interrelated; unresolved exterior leads to worsening interior, and disharmonious interior prevents exterior resolution. Thus, treating the interior can also resolve the exterior. There is a fixed order of priority regarding whether to treat exterior or interior, avoiding ambiguity. One must grasp the essence of the disease and discern the decisive factor for victory. This constitutes the treatment method for Yin-Yang Bingbing.

Since Yin pathology involves the Zang organs, which are the foundation of life and determine survival, diagnosing Yin diseases requires careful differentiation of deficiency and excess to ensure tonification, purgation, warming, and cooling are applied correctly. This is the most critical aspect of contemporary treatment.