Six-channel pattern identification

The process of diagnosing a morbid condition as a cold damage disease pattern affecting one or more of the six levels of penetration of disease evils that are named after the yīn-yáng designations of the channels (greater yáng (tài yáng), yáng brightness (yáng míng), lesser yáng (shào yáng), greater yīn (tài yīn), lesser yīn (shào yīn), reverting yīn (jué yīn)).

Cold-damage pattern identification is the system for diagnosing and treating disease according to the cold damage doctrine of externally contracted febrile disease. Because it identifies patterns on the basis of six levels of penetration of disease in the body, labeled by the names of the six main channels of the body, it is usually referred to as called six-channel pattern identification.

• Greater yáng (tài yáng) disease patterns
• yáng brightness (yáng míng) disease patterns
• Lesser yáng (shào yáng) disease patterns
• Greater yīn (tài yīn) disease patterns
• Lesser yīn (shào yīn) disease patterns
• Reverting yīn (jué yīn) disease patterns

Diseases that are caused by externally evils (as opposed to internal imbalances) and that are mostly marked by heat effusion (fever) in the initial stages are, according to cold damage theory, chiefly caused by wind or cold.

When these evils enter the body, they usually first settle in the greater yáng (tài yáng) channel, which is the most exterior of all the channels; if the disease is unresolved, it can progress through other channels, most commonly in the order of greater yáng (tài yáng), yáng brightness (yáng míng), lesser yáng (shào yáng), greater yīn (tài yīn), lesser yīn (shào yīn), and reverting yīn (jué yīn). Progression through all the channels is rare.

When the disease enters a given channel, specific patterns unique to that channel (and its associated bowel or viscus) arise, allowing the practitioner to diagnose and treat externally contracted disease at a specific stage of its development.

Origins

Six-channel pattern identification is the term now often used to describe the system of identifying the disease patterns of externally contracted febrile disease that was developed by the cold damage school based on the work of Zhāng Jī (Zhòng-Jǐng) of the Hàn Dynasty. Zhāng Jī wrote his ideas in the Shāng Hán Zá Bìng Lùn (伤寒杂病论, On Cold Damage and Miscellaneous Disease), a treatise on the diagnosis and treatment of a wide range of human diseases. The text was apparently lost during a period of political turmoil and was reassembled from fragments by Wáng Shū-Hé into two volumes, Shāng Hán Lùn (伤寒论 On Cold Damage) and Jīn Guì Yào Lüè (金匮要略 Essential Prescriptions of the Golden Cabinet). It is the Shāng Hán Lùn that forms the basis of the cold damage school’s understanding of externally contracted disease.

Zhāng Jī based his conception of externally contracted disease on the discussion of febrile disease in the Sù Wèn (Chapter 30, Rè Lùn). This text posited the notion that febrile disease, that is, disease that begins with the contraction of external evils and that is largely typified by heat effusion, at least in the initial stages. On the first day, it affects the greater yáng (tài yáng) (jù yáng). It advances to the yáng brightness (yáng míng) on the second day, to the lesser yáng (shào yáng) on the third, to the greater yīn (tài yīn) on the fourth day, to the lesser yīn (shào yīn) on the fifth, and to the reverting yīn (jué yīn) on the sixth. In the Sù Wèn conception, externally contracted disease was characterized by distinct signs in each of the channels. Zhāng Jī adopted the Sù Wèn idea that disease passed through the channels in this order but rejected the notion of daily progression. Zhāng Jī’s work is evidently based on much richer clinical experience than the scant statements in the Sù Wèn. For this reason, his work stood the test of time and prompted successive generations of scholars, especially after the Sòng Dynasty, to comment and elaborate on the system.

What follows is a simple description of the cold damage scheme. Each stage of penetration manifests in multiple patterns and variants, each with their own specific treatment. Here, we discuss only the main patterns and the main formulas used to treat them. For advanced study, we recommend Shāng Hán Lùn: On Cold Damage (Mitchell, Féng, and Wiseman, Paradigm Publications, 1999).

Channels and Signs

Six-channel pattern identification is a method of diagnosing cold damage. Each channel is a level of penetration of external evils and is associated with different signs. Changes in the clinical manifestations of a disease allow the practitioner to determine the channel in which the disease is located.

Yīn-Yáng

The six-channel pattern identification system is based on the principles of yīn and yáng.

• There are three yáng channels and three yīn channels.
• The yáng channels are associated with bowels; the yīn channels are associated with viscera.

The greater yáng (tài yáng) governs the exterior, yáng brightness (yáng míng) is in the interior, while the lesser yáng (shào yáng) is half exterior half interior. The three yīn channels belong to the interior.

Note that the yáng brightness (yáng míng) channels are those of the stomach and large intestine. While according to visceral manifestation theories, the stomach and large intestine stand in exterior-interior relationship with the spleen and lung respectively and hence are considered relatively exterior, yáng brightness (yáng míng) in cold damage theory is considered to be interior.

Note also that the names of the channels are used to label the stages of disease. It is important to understand, however, that the signs in each case are not necessarily the signs that are normally associated with the channels proper or with bowels and viscera with which the channels are linked by homing and netting.

As subcategories of yīn and yáng, the practitioner distinguishes between repletion and vacuity patterns. Yáng channel patterns are mostly repletion patterns, while yīn channel patterns are mostly vacuity patterns.

Association with the Bowels and Viscera

Although each of the six channels has two pathways each associated with a different viscus or bowel, six-channel patterns do not necessarily involve both organs. The yīn channel patterns to a greater or lesser degree all manifest in digestive problems.

• Greater yáng (tài yáng) disease affects the exterior (and the lung); in some cases, it affects the bladder (but not the small intestine).
• yáng brightness (yáng míng) disease can affect both the stomach and the large intestine.
• Lesser yáng (shào yáng) is affects the gallbladder (but not the triple burner).
• Greater yīn (tài yīn) disease affects the spleen (and stomach, but not the lung).
• Lesser yīn (shào yīn) is affects with the heart and kidney (and spleen).
• Reverting yīn (jué yīn) disease affects stomach and liver channel (but not the pericardium).

In the greater yáng (tài yáng) and yáng brightness (yáng míng) stages of disease, distinction is made between channel and bowel patterns. Here, channel patterns refers to generalized signs that are not necessarily strictly associated with the channel pathways. Bowel patterns, by contrast, does refer to disease affecting the bowels to which the channels home. In the case of greater yáng (tài yáng), bowel patterns denotes bladder patterns. In the case of yáng brightness (yáng míng), the term refers to stomach and intestine patterns.

Given the unsystematic relationship between the manifestations of disease in each stage and the organs to which the channels home, many scholars believe that the channels merely provide names for the stages of disease and cannot be seen as disease of the channels proper. Nevertheless, traditional discussions speak of the disease moving between channels rather than progressing or regressing from one stage or another, and modern discussions follow this conception.

Channel Passage

The disease signs of one channel can give way to those of another. This indicates that the disease has moved from one channel to another.

Sequential passage (循经传 xún jīng chuán): Sequential passage refers to the progression of the disease from one channel to another in the normal sequence. Depending on the body’s strength of resistance and on any treatment given, the disease can disappear at any stage; progression through all the channels is rare.

To this day, Chinese medical texts disagree on what the normal sequence is because, in practice, variations in progression are so numerous that it is difficult to say what the norm is. Nevertheless, the two following orders are recognized:

• Greater yáng (tài yáng) ð yáng brightness (yáng míng) ð lesser yáng (shào yáng) ð greater yīn (tài yīn) ð lesser yīn (shào yīn) ð reverting yīn (jué yīn). This sequence follows the order of the chapters in the Shāng Hán Lùn.
• Greater yáng (tài yáng) ð lesser yáng (shào yáng) ð yáng brightness (yáng míng) ð greater yīn (tài yīn) ð reverting yīn (jué yīn) ð lesser yīn (shào yīn). This is a more logical order insofar as it places lesser yáng (shào yáng) between the exterior greater yáng (tài yáng) and the interior yáng brightness (yáng míng).

Skipping channels (越经传 yuè jīng chuán): As a disease moves through different channels, sometimes a channel is skipped, e.g., as when the disease moves from greater yáng (tài yáng) to lesser yáng (shào yáng) without passing through yáng brightness (yáng míng).

Combination disease (合病 hé bìng): Signs associated with two or even three channels can appear at once, in which case it is called a combination disease.

Dragover disease (并病 bìng bìng): When the signs of one channel have not all disappeared and the signs of another channel are appearing, this is called a dragover disease.

Direct strike (直中 zhí zhòng): Sometimes, in patients with a weak constitution, disease evil entering the body skips all the yáng channels and moves directly into the yīn channels. This is called direct strike (on the interior) or cold strike (中寒 zhòng hán).

Transmuted pattern (变证 biàn zhèng): In wider context of disease progression, it should be noted that certain untoward developments are referred to as transmuted patterns (the word 变 biàn connoting change, especially of a sudden, substantial, or unfavorable nature). A transmuted pattern arises when, as a result of inappropriate treatment, such as inappropriate use of sweating or precipitation, a repletion converts into vacuity, or a simple condition becomes a more complex one. For example, excessive use of sweat-effusing medicinals in the treatment of greater yáng (tài yáng) cold damage patterns can cause detriment to heart yáng and cause heart palpitation or fearful throbbing and chest pain.

Six-Channel Patterns

Below is a brief description of the externally contracted disease patterns, with links to entries that provide more detail.

Greater yáng (tài yáng) disease patterns (太阳病证 tài yáng bìng zhèng): Greater yáng (tài yáng) disease arises when wind and cold invade the exterior. The main signs are aversion to wind or cold, headache, and a floating pulse. Sometimes this is accompanied by heat effusion, and tension and stiffness in the neck and back. The presence of sweating indicates wind strike (a vacuity pattern); the absence of sweating indicates cold damage (a repletion pattern). Rarely, the disease passes along the channel pathway into the greater yáng (tài yáng) bowel, i.e., the bladder, causing fullness in the smaller abdomen and inhibited urination or hardness of the lesser abdomen with black stool. See greater yáng (tài yáng) disease.

yáng brightness (yáng míng) disease patterns (阳明病证 yáng míng bìng zhèng): yáng brightness (yáng míng) disease usually arises when evil qì in the greater yáng (tài yáng) fails to resolve and passes into the yáng brightness (yáng míng) interior, transforming into heat in the process. See yáng brightness (yáng míng) disease.

• Channel pattern: If only the yáng brightness (yáng míng) channel is affected, there is great heat effusion; great sweating; great thirst; a pulse that is surging and large. These signs are often referred to as the four greats.
• Bowel pattern: If the yáng brightness (yáng míng) bowels (stomach and large intestine) are also affected, constipation with abdominal fullness and pain is also observed.

Lesser yáng (shào yáng) disease patterns (少阳病证 shào yáng bìng zhèng): Lesser yáng (shào yáng) disease usually arises when the debilitation of right qì allows an invading evil to bind in the gallbladder channel and affect the normal upbearing and downbearing of qì. The main signs are alternating heat effusion and aversion to cold (alternating cold and heat), fullness in the chest and rib-side, no thought of food or drink, heart vexation, retching, a bitter taste in the mouth, dry pharynx, dizzy vision, and a stringlike pulse. See lesser yáng (shào yáng) disease.

Greater yīn (tài yīn) disease patterns (太阴病证 tài yīn bìng zhèng): Greater yīn (tài yīn) disease can arise from inappropriate treatment or lack of appropriate treatment of disease of the yáng channels. It can also arise when, owing to spleen yáng vacuity, cold evil directly strikes the greater yīn (tài yīn). The main signs are abdominal fullness with periodic pain, vomiting, diarrhea, absence of thirst, and a pulse that is moderate (slightly slower than normal) and weak. See greater yīn (tài yīn) disease.

Lesser yīn (shào yīn) disease patterns (少阴病证 shào yīn bìng zhèng): Lesser yīn (shào yīn) disease arises in cold damage disease when the yīn and yáng of the body are weakened. It is centered in the heart and kidney. See lesser yīn (shào yīn) disease.

• Cold transformation: A yáng vacuity pattern manifesting in aversion to cold, curled-up lying posture, somnolence, severe cold of the limbs, and a pulse that is fine and faint. Diarrhea with undigested food in the stool may occur in some such cases.
• Heat transformation: A less common pattern of yīn vacuity with internal heat, manifesting as heart vexation, insomnia, and dry pharynx and mouth.

Reverting yīn (jué yīn) disease patterns (厥阴病证 jué yīn bìng zhèng): Reverting yīn (jué yīn) disease manifests in upper-body heat and lower-body cold. The main upper-body heat signs are thirst with a large intake of fluid, qì surging up into the heart, heat vexation in the heart, and clamoring stomach (a sensation similar to pain or hunger). The lower-body cold signs are no desire for food and vomiting of roundworms. See reverting yīn (jué yīn) disease.