Run Chang Wan: The Gentle TCM Solution for Constipation Relief

In TCM, the concepts of Blood and Yin are deeply interconnected, and understanding why Blood Deficiency can overlap with or even contribute to Yin Deficiency requires looking at their roles and relationship in the body.

Here’s an explanation:

Blood and Yin: A Close Relationship

• Blood as a Yin Substance: In TCM, Blood is considered a Yin substance because it is dense, nourishing, and moistening—qualities that align with Yin’s cooling, grounding, and hydrating nature. Blood provides the material foundation that nourishes organs, tissues, and the mind, much like Yin provides the fluids and substance that keep the body cool, calm, and lubricated.

• Yin as the Source of Blood: Yin, particularly Kidney Yin, is seen as the root that supports the production of Blood. The Kidneys store Essence (Jing), a deep Yin substance, which transforms into Marrow and contributes to Blood formation in conjunction with the Spleen and Heart. If Yin is deficient, the body struggles to generate adequate Blood.

How Blood Deficiency Can Be or Lead to Depletion of Yin or Yin Deficiency

1. Shared Functions: Both Blood and Yin moisten and nourish the body. Blood lubricates the intestines, skin, and eyes, while Yin ensures fluids (like saliva, sweat, and synovial fluid) are plentiful. A deficiency in Blood can impair these moistening functions, mimicking or exacerbating Yin Deficiency symptoms—think dry skin, dry mouth, or constipation.
2. Mutual Dependence: Blood and Yin rely on each other. Blood Deficiency can weaken the body’s ability to anchor and stabilize Yin, leading to signs like restlessness or heat (since Yin cools and calms). Conversely, Yin Deficiency can impair Blood production, as there’s insufficient fluid and essence to create it. This creates a vicious cycle where one deficiency feeds into the other.
3. Symptom Overlap: The symptoms of Blood Deficiency (pale face, dizziness, dull complexion, palpitations) and Yin Deficiency (night sweats, dry throat, thirst, heat sensations) often overlap because both involve a loss of nourishment and moisture. For example:
   • Dizziness: Blood Deficiency fails to nourish the brain; Yin Deficiency fails to anchor the mind.
   • Dryness: Blood Deficiency dries the skin and intestines; Yin Deficiency dries the throat and fluids.
4. Blood = Yin in Context: Saying "Blood = Yin" simplifies their relationship. Blood is a manifestation of Yin in the body—it’s the tangible, liquid form of Yin’s nourishing essence. When Blood is deficient, it’s often a sign that Yin is either depleted or unable to transform into Blood effectively.

Practical Example

In the case of Run Chang Wan, it treats constipation due to Blood Deficiency (dry intestines from lack of lubrication) and Yin Deficiency (depleted fluids causing dryness). The formula nourishes Blood (with Dang Gui) and Yin (with Sheng Di Huang), showing how these deficiencies are intertwined. If Blood Deficiency goes unchecked, it can drain Yin reserves, worsening the dryness and heat.

Why They’re Not Identical

While related, Blood Deficiency and Yin Deficiency aren’t always the same. Blood Deficiency often centers on the Liver and Heart (e.g., pale complexion, poor memory), while Yin Deficiency leans toward Kidney and Lung imbalances (e.g., tidal fever, night sweats). However, because Blood is a Yin substance and Yin supports Blood, a prolonged deficiency in one often pulls the other down.

In short, Blood Deficiency can be a form of Yin Deficiency because Blood embodies Yin’s nourishing, moistening essence. When Blood is lacking, Yin’s broader cooling and hydrating functions suffer too—making them two sides of the same coin in many TCM contexts!

Quick Tips

• When symptoms of Blood Deficiency predominate, Run Chang Wan proves to be an efficacious and appropriate therapeutic option.

• When symptoms of Yin Deficiency predominate, Zeng Ye Tang proves to be an efficacious and appropriate therapeutic option.