Qi, Blood, and Body Fluids: A Modern Interpretation

The Vital Substances of TCM

Classical Chinese medicine describes the body as animated by three fundamental substances: Qi (vital energy), Xue (Blood), and Jin-Ye (Body Fluids). These are not three separate things but three aspects of a single continuum — from the most rarefied and dynamic (Qi) to the most dense and material (Blood and Fluids). Disease, in TCM, is fundamentally a disorder of one or more of these substances: too much, too little, stagnant, deficient, or moving in the wrong direction.

Western medicine has no single concept equivalent to Qi — and this is where the cross-cultural misunderstanding begins. “Qi” has been variously translated as “energy,” “vital force,” “breath,” or “life force,” and each translation captures a fragment while missing the whole. Qi is not one thing. It is a functional category that encompasses multiple physiological processes Western medicine describes separately.

The purpose of this article is to map Qi, Blood, and Body Fluids to their modern physiological correlates — not to reduce them to Western terms (which loses the systemic perspective) but to build bridges between two descriptive systems that are examining the same body.

Qi: The Functions, Not the Substance

What Qi Does (The Six Functions)

Classical TCM does not define Qi by what it IS but by what it DOES. Qi has six classical functions, each mapping to specific physiological processes:

1. Transforming (Hua) Qi transforms food and air into usable energy and substance. This maps directly to: cellular metabolism — the conversion of macronutrients (carbohydrates, fats, proteins) and oxygen into ATP via glycolysis, the citric acid cycle, and oxidative phosphorylation in the mitochondria. When “Qi fails to transform,” the patient presents with fatigue, undigested food in stool, bloating, blood sugar dysregulation — the clinical picture of mitochondrial dysfunction, hypochlorhydria, and pancreatic enzyme insufficiency.

The mitochondrial connection is particularly compelling. Mitochondria — the “powerhouses of the cell” — produce approximately 90% of the body’s ATP through oxidative phosphorylation. They require substrates (from digestion — Spleen Qi), oxygen (from respiration — Lung Qi), and cofactors (CoQ10, B vitamins, magnesium, iron, copper). When any of these inputs are deficient, ATP production declines and the patient experiences what TCM calls “Qi Deficiency” and what functional medicine calls mitochondrial dysfunction. The symptom picture is identical: fatigue, exercise intolerance, brain fog, cold extremities, weakness.

Naviaux (2014, Mitochondrion) described the “cell danger response” (CDR) — a mitochondrial-mediated shift from normal energy metabolism to a defensive state, characterized by reduced ATP export, increased reactive oxygen species, and altered purinergic signaling. This maps remarkably to the TCM concept of Qi Stagnation transforming into Qi Deficiency under chronic stress.

2. Transporting (Yun) Qi moves substances through the body — nutrients to cells, waste to excretory organs, blood through vessels, food through the gut. This maps to: circulatory function, lymphatic drainage, gut motility (peristalsis), cellular transport mechanisms (ion pumps, carrier proteins), and microcirculation.

“Spleen Qi sinks” (Zhong Qi Xia Xian) — a pattern of organ prolapse, chronic diarrhea, and hemorrhoids — reflects a failure of the smooth muscle tone and fascial support that keeps organs in position and maintains proper peristaltic direction. Bu Zhong Yi Qi Tang, the classical formula for raising sinking Qi, has documented effects on smooth muscle tone and visceral support.

3. Holding/Containing (Gu) Qi holds things in place — blood in the vessels, organs in position, urine in the bladder, the fetus in the womb. This maps to: endothelial integrity, connective tissue tone, sphincter function, platelet and coagulation function, and fascial suspension. “Qi failing to hold Blood” produces easy bruising, heavy menstrual bleeding, petechiae — corresponding to capillary fragility, platelet dysfunction, or coagulation factor deficiency.

4. Protecting (Wei) Wei Qi — defensive Qi — circulates on the body’s surface and in the space between skin and muscle (the Cou Li), protecting against external pathogenic factors. This maps precisely to: mucosal immunity (secretory IgA), skin barrier function (antimicrobial peptides, tight junctions, microbiome), innate immune surveillance (NK cells, macrophages, dendritic cells), and the mucosa-associated lymphoid tissue (MALT) system.

“Wei Qi Deficiency” — catching every cold, allergies, frequent infections, autoimmune tendency — corresponds to: IgA deficiency, impaired mucosal barrier, microbiome dysbiosis, and innate immune dysfunction. Jade Wind Screen Powder (Yu Ping Feng San) — the classical formula for strengthening Wei Qi — contains Astragalus (Huang Qi), which modern research has shown enhances NK cell activity, increases IgA production, and modulates T-helper cell ratios (Block & Mead, 2003, Integrative Cancer Therapies).

5. Warming (Wen) Qi maintains body temperature. Yang Qi (the active, warming aspect of Qi) generates metabolic heat. This maps to: basal metabolic rate (governed primarily by thyroid hormones T3/T4), brown adipose tissue thermogenesis (uncoupling protein 1), and peripheral vasomotor regulation.

“Yang Deficiency” — cold extremities, low body temperature, fatigue worse in cold weather, pale complexion — corresponds to hypothyroidism, low metabolic rate, impaired peripheral circulation, and adrenal insufficiency (cortisol supports metabolic rate and vascular tone). See the parallel to Stage 3 HPA dysfunction described in ../functional-medicine/adrenal-hpa-axis-protocol.md.

6. Raising/Lifting (Sheng) Qi has a natural ascending movement that keeps organs lifted, maintains alertness, and supports upright posture. This overlaps with the Transporting and Holding functions but specifically addresses vertical orientation. “Qi sinking” produces prolapse, dizziness, fatigue, mental dullness — reflecting hypotension, autonomic dysfunction (POTS-like presentations), and insufficient cerebral perfusion.

Types of Qi

TCM distinguishes several types of Qi, reflecting different functional domains:

• Yuan Qi (Source Qi): Constitutional energy inherited from parents. Maps to: genetic endowment, mitochondrial DNA (inherited maternally), epigenetic programming, stem cell reserve. Stored in the Kidney.
• Gu Qi (Food Qi): Energy derived from digestion. Maps to: caloric energy, macronutrient metabolism, ATP from food. Generated by the Spleen/Stomach.
• Zong Qi (Gathering Qi): Formed from Gu Qi + air. Accumulates in the chest. Maps to: cardiopulmonary function — the combination of oxygen delivery (respiration) and nutrient energy (metabolism) that powers cardiac output and systemic circulation.
• Zheng Qi (Upright Qi): The totality of the body’s resistance to disease. Maps to: overall immune competence, homeostatic resilience, physiological reserve.
• Wei Qi (Defensive Qi): As described above — mucosal and innate immunity.
• Ying Qi (Nutritive Qi): Circulates with Blood in the vessels, nourishing tissues. Maps to: nutrient delivery via blood, oxygen-carrying capacity, microcirculation.

Qi as Bioelectricity

Beyond metabolism and immunity, Qi has a bioelectric dimension that is often underappreciated in modern TCM education. The body is an electrical system: transmembrane potentials (-70mV in neurons, -90mV in cardiac cells), action potentials, electrochemical gradients driving every ion pump, and direct current fields guiding wound healing and development.

Becker (1985) proposed that a DC electrical system, operating through the perineural connective tissue, constitutes a primitive communication system predating the nerve impulse — and that this system corresponds to the meridian network through which Qi flows. The coherent electromagnetic field of the body, measurable by SQUID magnetometry and electrodermal screening, may represent what classical practitioners perceived as Qi.

This is speculative but not implausible. When a patient with Qi Stagnation receives acupuncture and reports the sensation of “Qi moving” — a warm, tingling, spreading sensation along the meridian pathway — this may reflect the restoration of normal bioelectric flow through previously restricted fascial tissue.

Xue (Blood): More Than Red Cells

TCM Blood (Xue) overlaps with but is broader than hematological blood. Xue has functions beyond oxygen transport:

TCM Blood functions:

1. Nourishes tissues — delivers nutrients, moisture, and warmth to every cell
2. Houses the Shen — Blood anchors consciousness and emotional stability. When Blood is deficient, the Shen becomes unrooted: anxiety, insomnia, dream-disturbed sleep, difficulty concentrating, feeling ungrounded
3. Moistens — keeps skin, hair, tendons, eyes, and nails supple and hydrated

Modern correlates:

• Nutrient delivery: Blood carries glucose, amino acids, fatty acids, vitamins, and minerals to every tissue. “Blood Deficiency” (Xue Xu) maps to: iron deficiency anemia (the most obvious correlate), but also B12/folate deficiency, generalized malnutrition, poor absorption, and insufficient microcirculation.
• Oxygen transport: Hemoglobin-bound oxygen delivery. Blood Deficiency symptoms — fatigue, dizziness, pallor, shortness of breath on exertion — mirror anemia precisely.
• Hormonal transport: Blood carries all hormones to target tissues. “Liver Blood Deficiency” — scanty periods, dry eyes, poor night vision, brittle nails, dizziness — maps to low estrogen, low progesterone, and/or low iron, all of which impair tissue nourishment and menstrual regularity.
• Neurotransmitter precursor delivery: The “Blood houses Shen” concept becomes clear when you realize that Blood delivers tryptophan (serotonin precursor), tyrosine (dopamine/norepinephrine precursor), and other amino acids to the brain. Blood Deficiency → inadequate precursor delivery → neurotransmitter insufficiency → anxiety, insomnia, poor concentration. This is the biochemical mechanism behind “Blood failing to nourish the Heart” causing insomnia.
• Microcirculation: TCM Blood pathology includes “Blood Stasis” (Xue Yu) — Blood that is not moving properly, accumulating, and becoming sticky or clotted. This maps to: hypercoagulability, platelet aggregation, endothelial dysfunction, atherosclerosis, and impaired microcirculation. Blood Stasis signs — fixed sharp pain, dark complexion, purple tongue with dark spots, varicose veins, masses — are the clinical picture of vascular disease, fibroids, endometriosis, and thrombotic conditions.

The Blood-Qi Relationship: “Qi is the commander of Blood; Blood is the mother of Qi.” Qi moves Blood (cardiac output, vascular tone, peristalsis move blood through vessels). Blood nourishes Qi (delivering substrates for metabolism). When Qi stagnates, Blood stagnates. When Blood is deficient, Qi has no substrate to work with. This interdependence is why chronic stress (Qi Stagnation) eventually leads to structural changes (Blood Stasis) — functional medicine recognizes this as chronic stress → endothelial dysfunction → cardiovascular disease. The TCM model predicted the mechanism.

Jin-Ye (Body Fluids): The Aqueous Matrix

Jin-Ye — the Body Fluids — are divided into two categories:

Jin (Thin Fluids): Light, clear, mobile fluids that circulate with Wei Qi on the body’s surface and through superficial tissues. Maps to: sweat, tears, saliva, nasal mucus, interstitial fluid in superficial compartments, and cerebrospinal fluid.

Ye (Thick Fluids): Heavier, more viscous fluids that nourish deep structures. Maps to: synovial fluid in joints, cerebrospinal fluid (overlap with Jin), vitreous humor of the eyes, marrow, deep interstitial fluid, and mucus in the digestive and respiratory tracts.

Modern Correlates

Interstitial Fluid and the “Interstitium”: The landmark 2018 paper by Benias et al. (Scientific Reports) describing the interstitium — a previously unrecognized network of fluid-filled spaces supported by a collagen lattice — provided an anatomical substrate for Jin-Ye that TCM had described functionally for millennia. These interstitial spaces are found in the submucosa of the gut, the dermis, the peribronchial tissue, and the fascial planes — exactly where TCM locates the movement of body fluids.

Lymphatic System: The lymphatic system — underappreciated in Western medicine until the 2015 discovery of meningeal lymphatics by Louveau et al. (Nature) — is a primary vehicle for Ye (thick fluid) circulation. Lymphatic fluid is rich in immune cells, waste products, and large molecules. “Dampness” in TCM — the pathological accumulation of turbid fluids causing heaviness, swelling, brain fog, and mucus — corresponds to lymphatic stasis, impaired lymphatic drainage, and the accumulation of metabolic waste in interstitial spaces.

Cerebrospinal Fluid: The CSF, produced by the choroid plexus and circulating through the ventricular system and subarachnoid space, nourishes the brain and spinal cord and removes metabolic waste. TCM classifies the brain as a “Curious Organ” (Qi Heng Zhi Fu) nourished by Kidney Essence and marrow — and the CSF, which bathes and nourishes neural tissue, is a form of Ye (thick fluid). The glymphatic system (Iliff et al., 2012, Science Translational Medicine) — the brain’s waste clearance system that operates primarily during deep sleep — adds another layer: TCM’s observation that Shen (consciousness/spirit) requires adequate Yin (fluids) to be anchored, and that Yin Deficiency causes insomnia and restlessness, maps to the glymphatic finding that sleep deprivation impairs waste clearance, leading to neuroinflammation and cognitive dysfunction.

Mucus and Biofilms: “Phlegm” (Tan) in TCM — a pathological condensation of body fluids into thick, obstructing substances — represents one of the most clinically important concepts in Chinese medicine. Phlegm obstructs channels, clouds the mind, forms masses, and creates disease in virtually every organ system. Modern correlates include:

• Respiratory mucus overproduction (asthma, COPD, sinusitis)
• Atherosclerotic plaque (Phlegm obstructing the Heart vessels)
• Lipomas and cysts (Phlegm accumulating in soft tissue)
• Biofilms in the gut (microbial Phlegm obstructing digestion)
• Demyelination and neurological Phlegm (multiple sclerosis, stroke)
• Metabolic syndrome — elevated triglycerides, visceral adiposity, insulin resistance (Phlegm-Dampness pattern)

The concept of “Phlegm misting the mind” (Tan Mi Xin Qiao) — causing confusion, disorientation, cognitive impairment, and even psychosis — maps to neuroinflammation, cerebral small vessel disease, and the metabolic-inflammatory cascade now recognized as contributing to dementia, delirium, and psychiatric illness.

Pathological Patterns: A Diagnostic Framework

Qi Deficiency (Qi Xu)

TCM presentation: Fatigue, shortness of breath, weak voice, spontaneous sweating, poor appetite, loose stools, pale tongue with thin white coating, weak/empty pulse FM correlation: Mitochondrial dysfunction, hypothyroidism, adrenal insufficiency, malabsorption, anemia, chronic fatigue syndrome Key labs: Comprehensive metabolic panel, thyroid (TSH, FT3, FT4, RT3), ferritin, B12, folate, DUTCH cortisol

Qi Stagnation (Qi Zhi)

TCM presentation: Distension and fullness (especially epigastric, hypochondriac, or abdominal), mood swings, sighing, PMS, variable symptoms that move locations, wiry pulse FM correlation: Sympathetic dominance, elevated cortisol, estrogen dominance, bile stasis, functional GI disorders, anxiety/depression Key labs: Cortisol (DUTCH or salivary), estrogen metabolites, liver function, GI-MAP

Blood Deficiency (Xue Xu)

TCM presentation: Dizziness, blurred vision, floaters, pale face and lips, dry skin and hair, scanty menses or amenorrhea, insomnia, anxiety, numbness/tingling, pale tongue, thin/choppy pulse FM correlation: Iron deficiency anemia, B12/folate deficiency, low estrogen, low progesterone, malabsorption Key labs: CBC with indices, ferritin (optimal >50 ng/mL), iron panel, B12, folate, RBC folate, estradiol, progesterone

Blood Stasis (Xue Yu)

TCM presentation: Fixed stabbing pain, dark complexion, spider veins, varicose veins, dark menstrual blood with clots, masses, purple tongue with dark spots, choppy or firm pulse FM correlation: Hypercoagulability, endothelial dysfunction, atherosclerosis, endometriosis, fibroids Key labs: Fibrinogen, D-dimer, homocysteine, Lp(a), hsCRP, ultrasound imaging

Dampness (Shi)

TCM presentation: Heaviness, sluggishness, brain fog, edema, loose stools, mucus, greasy tongue coating, slippery pulse FM correlation: Lymphatic stasis, microbiome dysbiosis, candidal overgrowth, insulin resistance, histamine intolerance Key labs: Fasting insulin, HOMA-IR, lipid panel, organic acids (yeast markers), food sensitivity testing

Phlegm (Tan)

TCM presentation: Masses, nodules, obesity, atherosclerosis, seizures, mental confusion, heavy limbs, productive cough, swollen tongue with thick greasy coating, slippery/wiry pulse FM correlation: Metabolic syndrome, atherosclerosis, lipomas, cysts, biofilms, neuroinflammation Key labs: Advanced lipids (LDL-P, sdLDL), triglycerides, HbA1c, inflammatory markers, MRI for structural lesions

Yin Deficiency (Yin Xu)

TCM presentation: Night sweats, hot flashes, malar flush, five-palm heat (heat in palms, soles, and chest), dry mouth and throat, thirst, tinnitus, scanty dark urine, red tongue with no coating, thin/rapid pulse FM correlation: Menopausal/andropausal hormone decline, chronic dehydration, adrenal exhaustion (late stage), autonomic dysregulation, chronic inflammation depleting yin reserves Key labs: Estradiol, testosterone, DHEA-S, cortisol (DUTCH), inflammatory markers, electrolytes

Yang Deficiency (Yang Xu)

TCM presentation: Cold extremities, low body temperature, fatigue, edema (especially lower body), low libido, frequent pale urination, low back and knee weakness, pale swollen tongue with wet coating, deep/slow pulse FM correlation: Hypothyroidism, low testosterone, HPA Stage 3, low aldosterone, metabolic rate decline Key labs: Full thyroid panel, testosterone (free and total), DUTCH cortisol, aldosterone, renin

Clinical Integration

The genius of the TCM vital substances framework is that it provides a clinical shorthand for complex physiological states. When a practitioner diagnoses “Spleen Qi Deficiency with Dampness and Blood Stasis,” they are describing: digestive insufficiency (low enzymes, poor absorption) → metabolic waste accumulation (lymphatic stasis, microbiome dysbiosis) → circulatory impairment (endothelial dysfunction, poor microcirculation). This three-part diagnosis generates a treatment strategy that addresses all three layers simultaneously — something that a fragmented Western approach (GI specialist for digestion, rheumatologist for inflammation, cardiologist for vascular issues) often fails to do.

The vital substances are not metaphors. They are a different parsing of the same physiology. Learning to think in both systems — the molecular specificity of Western medicine and the systemic pattern recognition of TCM — creates a clinical perspective more complete than either alone.

Cross-Connections

• For the meridian pathways through which these substances flow: see meridian-system-bioelectric-network.md
• For organ systems that produce and regulate these substances: see zang-fu-organ-theory-functional-medicine-bridge.md
• For herbal formulas that address these patterns: see chinese-herbal-formulas-classical-protocols.md
• For the HPA axis connection to Qi and Yang: see ../functional-medicine/adrenal-hpa-axis-protocol.md
• For gut-brain axis and Dampness: see acupuncture-digestive-disorders-gut-brain.md

References

• Becker, R. O., & Selden, G. (1985). The Body Electric: Electromagnetism and the Foundation of Life. William Morrow.
• Benias, P. C., Wells, R. G., Sackey-Aboagye, B., et al. (2018). Structure and distribution of an unrecognized interstitium in human tissues. Scientific Reports, 8, 4947.
• Block, K. I., & Mead, M. N. (2003). Immune system effects of echinacea, ginseng, and astragalus: a review. Integrative Cancer Therapies, 2(3), 247-267.
• Iliff, J. J., Wang, M., Liao, Y., et al. (2012). A paravascular pathway facilitates CSF flow through the brain parenchyma and the clearance of interstitial solutes, including amyloid beta. Science Translational Medicine, 4(147), 147ra111.
• Louveau, A., Smirnov, I., Keyes, T. J., et al. (2015). Structural and functional features of central nervous system lymphatic vessels. Nature, 523(7560), 337-341.
• Maciocia, G. (2015). The Foundations of Chinese Medicine (3rd ed.). Churchill Livingstone/Elsevier.
• Naviaux, R. K. (2014). Metabolic features of the cell danger response. Mitochondrion, 16, 7-17.
• Wiseman, N., & Ye, F. (1998). A Practical Dictionary of Chinese Medicine (2nd ed.). Paradigm Publications.