Marrow
Marrow (Sui) is one of the six Extraordinary Fu organs in TCM, produced by Kidney Essence. It nourishes the brain and spinal cord, strengthens bones, and participates in blood production. Unlike Western medicine's bone marrow concept, TCM Marrow encompasses bone marrow, spinal cord, and brain substance.
Five Element Correspondences
Season
Winter
Climate
Cold (via Kidney)
Emotion
Fear (via Kidney)
Color
Black (via Kidney)
Taste
Salty (via Kidney)
Sound
Groaning (via Kidney)
Direction
North
Sense Organ
Ears (via Kidney connection)
Body Tissue
Bones and Brain
Body Fluid
Essence (Jing)
Peak Hours
17-19 (follows Kidney)
Meridian
Kidney Meridian
Educational content · Consult qualified TCM practitioners for diagnosis and treatment
Overview
Marrow (Sui 髓) is one of the six Extraordinary Fu organs (Qi Heng Zhi Fu 奇恒之腑) in Traditional Chinese Medicine. Unlike the regular Fu organs that transport and transform food, the Extraordinary Fu organs are characterized by being hollow in form like Fu organs but storing essence like Zang organs—hence they "store but do not drain."
In TCM, Marrow is not limited to the Western concept of bone marrow. It encompasses three interconnected substances: bone marrow that fills the bones, spinal marrow that runs through the spine, and brain marrow that fills the skull. The brain is called the "Sea of Marrow" (Sui Hai 髓海) because all marrow ultimately gathers there. This concept helps explain why the Kidneys, which produce Marrow, are so intimately connected with brain function, cognitive abilities, and skeletal health.
Marrow originates from Kidney Essence (Jing). When Kidney Essence is abundant, Marrow is plentiful, leading to strong bones, a sharp mind, good memory, and clear senses. When Kidney Essence becomes depleted—through aging, chronic illness, or excessive lifestyle—Marrow becomes deficient, manifesting as weak bones, poor memory, dizziness, and mental dullness.
Historical Context
The concept of Marrow as an Extraordinary Fu organ was established in the foundational text of Chinese medicine, the Huangdi Neijing (Yellow Emperor's Inner Classic), compiled around 200 BCE. The Su Wen (Simple Questions) Chapter 11 first categorized the six Extraordinary Fu organs, stating that "the brain, marrow, bones, vessels, gallbladder, and uterus... store but do not drain, and are called the Extraordinary Fu organs."
Classical texts developed the understanding that Kidney Essence transforms into Marrow. The Su Wen states "all marrow belongs to the brain" (诸髓者，皆属于脑), establishing the relationship between Marrow and brain function. Later physicians like Li Shizhen (Ming Dynasty) further clarified that "the brain is the residence of the primordial spirit," connecting Marrow health to consciousness and mental activities. Some scholars debate whether Marrow should be considered a physical organ or rather a vital substance like Qi or Blood, given its fluid nature and lack of distinct anatomical form.
Physiological Functions
Nourishes the Brain
养脑 (Yǎng Nǎo)Marrow rises up through the spine to fill and nourish the brain, which TCM calls the "Sea of Marrow." When brain marrow is sufficient, mental faculties are sharp—thinking is clear, memory is strong, and concentration is good. This function explains why Kidney-nourishing treatments can help cognitive problems.
Strengthens the Bones
养骨 (Yǎng Gǔ)Bone marrow fills the hollow cavities within bones, providing nourishment that keeps bones strong and resilient. The saying "bones are the residence of marrow" reflects this intimate relationship. Healthy marrow creates sturdy bones; depleted marrow leads to weak, brittle bones prone to fractures.
Generates Blood
化血 (Huà Xuè)TCM recognized that Marrow participates in blood production, as stated in classical texts: "essence generates marrow, marrow can transform into blood." This understanding parallels modern knowledge that bone marrow produces blood cells. Clinically, some blood disorders are treated by nourishing Kidney Essence and filling Marrow.
Supports Sensory Function
主感官 (Zhǔ Gǎn Guān)Because the sense organs connect to the brain, adequate brain marrow supports clear vision, sharp hearing, keen smell, and proper taste. When the Sea of Marrow is depleted, symptoms like tinnitus, blurred vision, and dizziness can occur.
Relationships with Other Organs
Generating
The Kidney is the primary source of Marrow. Kidney Essence (Jing) transforms into Marrow, which then fills the bones, spine, and brain. This is the most fundamental relationship—"the Kidney governs the bones and produces Marrow." When Kidney Essence is abundant, Marrow flourishes; when depleted, Marrow withers. All treatments for Marrow deficiency ultimately focus on nourishing the Kidney.
Other
The Brain is called the "Sea of Marrow" because it is where all Marrow gathers and accumulates. The Brain depends entirely on Marrow for its nourishment and proper function. This relationship explains why cognitive function, memory, and mental clarity are affected when Marrow is deficient.
Generating
While Kidney Essence is the primary source of Marrow, the Spleen contributes through post-natal essence. Food essence refined by the Spleen can "seep into the bone cavities to supplement brain marrow." This means adequate digestion and nutrition support Marrow health throughout life, supplementing what we're born with.
Other
The Liver stores Blood, and Blood and Essence can mutually transform. Marrow can generate Blood, and Blood can nourish Marrow. Additionally, the Liver's role in governing sinews works together with Marrow's support of bones to enable smooth movement. Liver Blood deficiency can contribute to Marrow insufficiency.
Common Pathological Patterns
Key Manifestations
Tongue Manifestations
Marrow deficiency primarily shows as a pale tongue body, reflecting the underlying Kidney Essence deficiency and reduced blood production. The tongue may also appear thin and dry when Yin aspects are depleted. In severe or chronic cases, the tongue may develop cracks (particularly a midline crack extending toward the root) indicating constitutional weakness. The coating is typically thin and white unless other pathogenic factors are present. Since Marrow deficiency often accompanies aging, an elderly patient's tongue may show multiple signs of deficiency.
Pulse Manifestations
The characteristic pulse of Marrow deficiency is deep (Chen) and weak (Ruo), particularly noticeable at the Kidney position (both Chi positions at the wrists). The pulse may also be thready or fine (Xi), reflecting insufficient blood and essence. In cases where blood production is affected, a choppy (Se) quality may be present. The overall pulse lacks strength and vitality, feeling empty or hollow upon deeper palpation, indicating that the fundamental substances are depleted.
Clinical Relevance
Understanding Marrow is clinically important for treating conditions involving bones, brain, blood, and aging. Because Marrow originates from Kidney Essence, most therapeutic approaches focus on tonifying the Kidneys. The acupuncture point GB-39 (Xuanzhong) is specifically designated as the Influential Point for Marrow and is commonly used in treatments for bone disorders, cognitive decline, and certain blood conditions.
Clinical conditions where Marrow deficiency plays a role include: osteoporosis and bone weakness, cognitive decline and dementia, certain types of anemia (particularly aplastic anemia), developmental delays in children, premature aging, chronic fatigue with weakness, and recovery from chemotherapy or serious illness. Treatment typically combines Kidney-tonifying herbs like Shu Di Huang, Lu Rong, and Gui Ban with acupuncture to nourish Essence and fill Marrow. Modern research on bone marrow transplantation and stem cell therapy has interesting parallels with TCM's understanding of Marrow's regenerative importance.
Classical Sources
Huangdi Neijing Su Wen
Chapter 11 (Wu Zang Bie Lun)脑、髓、骨、脉、胆、女子胞，此六者，地气之所生也，皆藏于阴而象于地，故藏而不泻，名曰奇恒之府
The brain, marrow, bones, vessels, gallbladder, and uterus—these six are generated by Earth Qi, all store Yin and correspond to Earth, therefore they store but do not drain, and are called the Extraordinary Fu organs.
Huangdi Neijing Ling Shu
Chapter 33 (Hai Lun)脑为髓之海
The brain is the Sea of Marrow.
Huangdi Neijing Su Wen
Chapter 10 (Wu Zang Sheng Cheng)诸髓者，皆属于脑
All marrow belongs to the brain.
Huangdi Neijing Su Wen
Chapter 17 (Mai Yao Jing Wei Lun)髓海不足，则脑转耳鸣，胫酸眩冒，目无所见
When the Sea of Marrow is insufficient, there is dizziness, tinnitus, aching legs, vertigo, and inability to see.
Modern References
The Foundations of Chinese Medicine
Comprehensive coverage of Extraordinary Fu organs including Marrow, with clinical applications for modern practice.
Traditional Chinese Medicine for Treating Aplastic Anemia
Reviews TCM approaches to bone marrow failure, validating traditional understanding of Marrow's blood-generating function.
Chinese Acupuncture and Moxibustion
Standard TCM textbook covering the theoretical basis and acupuncture treatment of Marrow-related conditions.