The Curious Concept of Latency: The Luo Vessels

The Chinese medical classics emphasize importance in understanding "transmission" within the disease process. It is not enough to view a condition in its present state alone; one must understand where it has come from and where it could potentially progress to next. Book 2, Chapter 5 of the Jia Yi Jing states "If one doesn't understand root and termination, knowledge of acupuncture is deeply severed." The foundational texts of classical Chinese medicine, namely the Shang Han Lun and Nei Jing, devote much time to discussion of disease progression. Classical treatment aims to address the past, present and future of a condition.

Chinese medicine is preventative, palliative and convalescent medicine; it helps prevent and heal from disease, as well as rebuild and regenerate the body. According to Classical Herbal Medicine's Shen Nong Ben Cao, the highest form of medicine is considered preventative; herbs classified as preventative are considered "highest grade." Treatment of an actual disease is considered "lower grade." Herbal formulas are often composed of herbs from all three grades, treating the present stage of the condition, as well as its origin. Formulas often attempt to prevent transmission into deeper stages of disease penetration as well. Acupuncture, as practiced within the classical tradition, formulates channel and point combinations in much the same way.

The Ling Shu makes use of the six channel systems to teach disease progression from an acupuncture point of view. Understanding transmission and progression are central to most discussions within classical Chinese medicine. Shang Han Lun is a treatise on disease progression. The Primary Channels, as taught by the Ling Shu, are also a treatise on disease progression. They are not presented as segmented entities in the Ling Shu; they are seen as a continuum, representing the pathological process: from the most external condition to the deepest and most serious. Instead of viewing disease progression in terms of "zones": Tai Yang, Shao Yang, Yang Ming, as Shang Han Lun does; the Ling Shu views disease progression through the Primary Channels they are coupled into Metal, Earth, Fire, Water, Fire, Wood: Lung to Liver.

During the time of the Han Dynasty (206 BCE – 220 CE), when the Nei Jing and Shang Han Lun were compiled, wind and cold were seen as the primary causes of external pathology. Heat, damp, dryness and summer heat were considered transformations of wind and cold, and therefore seen as secondary. Within the Ling Shu, the Lung Channel is representative of a wind-cold condition; therefore it is designated the first channel within the Primary Channel continuum. The transformation of wind-cold into wind-heat and wind-damp is represented by the second channel in the continuum: the Large Intestine. Penetration into the interior, creating an "excess" internal condition is represented by the Stomach. Taxation on qi and blood are represented by the Spleen and Heart channels, respectively.

At the level of the Small Intestine, a curious event occurs within the body. The pathogen gets absorbed into the deeper terrain of the body: into a state of latency. The level of the Small Intestine represents a blood stasis state. It also introduces the concept of latency. The points Small Intestine 18 "Cheekbone Liao" and Small Intestine 12 "Grasping the Wind" represent the absorption of an unresolved pathogenic factor into the bones, as represented by the scapula and cheekbone. From the Ling Shu Primary Channel discussion, it is suggested that latency can involve the blood and bones.

Latency hides a pathogenic factor. This is the stage where conditions become insidious and mysterious. The immune system of the body may be over-acting or the humors of the body continually deficient, yet the cause may be unclear. A viral or bacterial agent may not show up in Western blood tests during a state of latency. However, understanding disease progression, an educated Chinese medical practicioner may be able to explain the mysterious symptoms. Many such "mysterious" symptoms are attributed to the Luo Vessels and Divergent Channels: two channel systems that deal with latency via the blood and bones.

A Classical Chinese acupuncturist might argue that knowledge of the Primary Channels alone is not enough to understand the subtle concepts of Chinese Medicine, such as latency. The so-called "Secondary Channels" of acupuncture provide more in-depth discussion into the concept of latency and how it works within the body. The Luo Vessels and Divergent Channels are two channel systems that provide the greatest insight into the concepts and treatment of latency. I would like to focus primarily on the Luo Vessels.

The Luo Vessels

The Luo Vessels are channels of latency. They hold onto pathogenic factors. Luo Vessels are conduits of ying "nourishing" qi: blood and the jinye body fluids. Within the theory of the "Antique" or "Five Shu-Transporting" Points, the Luo point, located after the shu-stream point, illustrates the function of the Luo Vessel Channel System. The shu-stream point represents the division between the external and internal levels of the body. By the time a pathogen reaches the Luo point, it has already entered the interior, suggesting the external "wei level" has failed to keep the condition on the exterior. At this stage, there is danger the pathogen could move into the internal branch of the Primary Channel where it will have access to the Zang or Fu organ. From the Luo point, a "collateral" is formed to translocate the pathogen away from the Primary Channel, where it can be held in a state of latency. The Luo Vessels use "ying qi" to maintain the state of latency.

The Sinew Channels represent the most superficial level of qi within the body: they are conduits of wei "defensive" qi. They are the body's first defense against the environment and external pathogenic factors. Wei qi is supported by ying qi, produced in the stomach from the jinye fluids. It is also supported by yang qi, rooted in the Kidneys.

The Nan Jing teaches, through the principles of yin and yang, the concept of mutual transformation. Ying qi supports the "wei level" through transforming itself into reinforcements for wei qi. The more severe a condition, the more reinforcements are called for. The Nan Jing also teaches that excess leads to deficiency, and deficiency leads to progression. When a pathogenic factor is severe, it can create deficiency, exhausting wei qi and the humors that support it.

The Shang Han Lun School gives clues as to progression within the Yang Stages of an external condition. Within the initial Tai Yang stage associated with "wind-cold," one can predict where the condition is likely to progress based on deficiencies that already exist, or those which are beginning to show up. Progression into the Yang Ming stage is predicated on the jin ("thin") fluids produced by the stomach. If the jin fluids become exhausted, it is likely the Tai Yang condition will progress into the Yang Ming stage. Whereas, if yang qi is insufficient or becoming taxed, the condition is likely to progress into Shao Yang.

When the Yang Sinew Channels fail, the pathogen moves into the Yin Sinews, which are located in the regions of the throat, chest and abdomen. Chapter 5 of the Ling Shu presents an interesting discussion entitled "Roots and Terminations." All the acupuncture channels of the legs are described as beginning at the Jing Well point and "terminating" at specific local points on the body. The Yang channels terminate in the region of the head; the Yin Channels terminate in the throat, chest and abdomen. The channel descriptions are not those of the Primary Channels; they resemble more closely the Sinew Channels, which also begin at the Jing Well points.

Chapter 5 suggests that unresolved pathogens will accumulate in the "terminations" of the body: the sense orifices, throat, chest and abdomen. The accumulations are associated with the jin fluids, which are "reinforcements" for the wei qi. These accumulations can be seen as the unsuccessful attempts by the wei qi to discharge a pathogenic factor, transforming into "turbidity," leading to the blockage and ultimate failure of the Sinew Channels.

When the Sinew Channels fail as the body's first defense against external pathogenic factors, another channel system inherits the problem. The second line of defense is the Luo Vessels. When an issue finds its way into the Luo Vessels, it suggests that the pathogen has become too overwhelming for the wei level to release, or that the body has become too weak to do so. The Luo Vessels represent the first stage within the channel systems where latency is employed by the body.

The so-called "Secondary Channels" of acupuncture indirectly support the daily flow of qi and blood, as represented by the 12 Primary Channels. Their goal is to prevent a pathogenic factor from making its way into the Primary Channels and Zang Fu where it could potentially disrupt daily physiological function.

When the wei level of the body has shown itself incapable of "releasing" a pathogenic factor, the body has no choice but to hold onto it. To prevent movement into the Primary Channels and Zang Fu, the Luo Vessels trap the pathogenic factor in a minor blood vessel, which is created on the surface of the skin. The ying level brings its commodity of blood to the surface of the body, which manifests as varicosity: a form of latency. This is classically known as "fullness of the Luo."

Latency can be a life-saver, but it is also taxing on the resources of the body. The blood used to maintain a latent state is pulled away from other areas of the body. The stomach must continually create blood to finance the latency. The latency, which is essentially a form of "blood stasis" blocks qi and blood movement. Also, anything being held within the body will generate heat, which will further consume blood, qi and yin, creating further taxation. Latency is not free; it has its price.

When the blood becomes insufficient, and the body can no longer afford to finance the latency with this commodity, the ye fluids will begin to support. This manifests in swellings, nodules and lipomas on the surface of the body: classically known as "emptiness of the Luo." The ye is the substance which post-natally supports the pre-natal yin of the body. The Ling Shu teaches that the ye fluids nourish the Zang Fu and Curious Fu. Use of the ye to support latency essentially robs the organs of nourishment. Luo Vessel theory explains how taxation from a chronically unresolved pathogenic factor can lead to blood and yin deficiency within the body.

Symptoms of the Luo Vessels relate to Bi obstruction, rebellious qi, and Shen disturbances. Luo issues commonly affect the "lesser articulations" - joints of the fingers, toes and elbows. Signs of Luo Vessels manifest as "visibility," which can be interpreted in many ways. "Fullness" and "emptiness" of the Luo classically show up as spider veins or swellings on the surface of the skin. However, any visibility can indicate a Luo issue, including emotional demeanor and changes in skin complexion: essentially anything that can be seen. This is chiefly the way Luo Vessel issues are diagnosed: through visibility.

The language used in describing Luo Vessel signs and symptoms are two-fold. They are described in Chapter 10 of the Ling Shu in somatic terms, often relating to symptoms of Bi obstruction and rebellious qi. However, the symptoms can also be seen as somatic representations of the psychological.

The Luo Vessels are considered pathological channels, created by the body as needed. They do not follow the same trajectory flow as the Primary Channels. In Chapter 10 of the Ling Shu, the Luo Vessels are described as flowing from the Lung Luo to the Heart and Pericardium Luo, to the Small and Large Intestine Luo to the Triple Heater Luo: Yin Arm Channels into Yang Arm Channels. They continue into the Bladder and Gallbladder Luo and Stomach Luo, before finishing in the Yin Channels of the Legs: Spleen, Kidney and Liver Luo. As, they are conduits of ying qi, 19th Century military doctor Wang Qing Ren has commented that the Luo channels, as presented by the Ling Shu, are the ancient Chinese description of the circulatory system: the circulatory system as it becomes pathological.

The Luo Vessels communicate with only a few of the Zang Fu: the Heart, Pericardium, Stomach and Intestines. The Jia Yu Jing designates regulatory functions to the Fu organs, relating to the humors of the body. The Stomach is said to control blood, while the Large and Small Intestine control the jin and ye fluids, respectively. Luo Vessel issues impact blood and yin, disrupting the organs that control them.

In Chinese Medicine, the Shen is believed to be "housed" in the Heart. Wang Qing Ren comments that the Heart is responsible for external circulation of blood, while the Pericardium controls systemic-internal circulation. Classically, the Stomach is seen as the organ that produces blood. The jinye is the precursor to blood. Blood supports the yin, and the ye fluids support the blood.

The Shen circulates through the blood. Luo Vessels are channels of latency: they deal with latency that is held in the blood. Classically, anything related to blood, is also related to the Shen. The blood stasis state induced by the Luo Vessels, as they are creating and maintaining latency, can also be seen as "Shen stasis." My teacher Jeffrey Yuen has often referred to this as "psycho-sclerosis."

Latent pathogens can originate from the exterior or interior of the body: coming from the world, or from the self. The seven emotions are considered "internal pathogenic factors." The Luo Vessels deal with internalized external pathogenic factors, as well as internal pathogenic factors themselves. My next article will discuss the Luo Vessels in relation to psychological, psycho-somatic and emotional disturbances: the layers of repression, suppression and denial.