Anatomy in a Linguist’s Eyes: From “Boiling Blood” to “Big Liver”

How Organs Become Metaphors Across Language, Culture, and Emotion

Why do we say our blood is boiling when we’re angry, or refer to someone who is bold as “big-livered” in Korean? Across cultures and throughout history, the human body has been more than just biology. It has served as a powerful metaphor for inner life. For linguists, anatomy offers a window into how people understand emotion, motivation, and character through physical terms. This process, referred to as embodied cognition (Lakoff and Johnson, 1980), helps explain why we speak of hearts as heavy, stomachs as turning, or nerves as frayed. These expressions reveal a universal instinct to make sense of what we feel by pointing to what we can touch.

Although languages differ in which organs they emphasize, the underlying logic remains surprisingly consistent. Emotions that feel hot, heavy, sharp, or unstable are often linked to parts of the body we associate with similar sensations. In English, rage bubbles up like boiling blood, while courage is said to come from the heart or backbone. In Korean, the liver becomes the seat of nerve and boldness, with phrases like "(someone’s) liver is big" used to praise audacity. These patterns suggest that metaphor is not simply decorative. It is a cognitive strategy that turns physical experience into emotional vocabulary.

Metaphors by Organ: A Cross-Cultural Anatomy of Emotion

1. Heart - Openness, Sorrow, and Joy

The heart is one of the most universally metaphorized organs. In English, someone may be open-hearted or heavy-hearted, revealing emotional transparency or sadness. The heart also hosts joy in many cultures. In Chinese, the phrase 心花怒放(lit. the heart blossoms like a flower) vividly describes happiness that feels expansive and joyful.

In Traditional Chinese Medicine (TCM), the heart governs the shen, or spirit. This aligns with metaphors that associate heart function with clarity of mind, emotional presence, and connection.

2. Liver - Boldness, Anger, and Volatility

The liver plays a central role in emotional metaphor across Asia. In Korean, expressions like 간이 크다 ("liver is big") praise someone for their nerve or courage. In contrast, 간이 작다 ("small liver") describes timidity. When the liver trembles, it signals fear, and if it protrudes, it signals reckless boldness.

In TCM, the liver governs anger and the smooth flow of Qi. When this flow is blocked, emotions can erupt. Korean idioms like 피가 거꾸로 솟다 ("blood surges upward") reflect this explosive sensation, echoing what in English we call "boiling blood."

3. Stomach and Gut - Intuition, Anxiety, and Instinct

English is rich in gut metaphors: gut feeling suggests instinctive knowing, while butterflies in the stomach describes nervous anticipation. These phrases reflect the visceral sensitivity of the digestive system and mirror scientific findings on the brain and gut connection.

In TCM, the spleen and stomach are affected by worry and overthinking. When the liver overacts on the spleen and the stomach, as described in syndrome theory, it can create physical unease and emotional instability - a pattern well captured by the metaphor my stomach turns when I’m stressed.

4. Skin - Sensitivity and Boundaries

Expressions like thin-skinned, rubbed the wrong way, or gets under my skin connect emotional sensitivity to the body’s outermost layer. Skin metaphors often describe irritability, vulnerability, or emotional exposure.

Although skin is less emphasized in TCM organ theory, it is governed by the lungs, which are tied to grief and the body’s protective barrier (Wei Qi). Linguistically, skin serves as a boundary between self and the world, just as emotionally sensitive people may feel porous to external influence.

5. Kidneys - Fear and Survival

Though archaic in English, phrases like put the fear of God in his kidneys reflects an older link between deep-seated fear and the lower body. Modern expressions like knees knocking preserve this link, showing how intense fear still visibly unsettles the lower body.

Similarly, in TCM, the kidneys are the foundation of life force and the root of fear. Deficient kidney energy (Qi) can result in panic, trembling, or insecurity. Korean and Chinese expressions that reflect bodily trembling in fear may align with this model, grounding emotional reactions in physical weakness.

Conclusion: The Body as a Language of Emotion

From boiling blood in English to a trembling liver in Korean, human language reveals a deep truth. We understand emotion by mapping it onto the body. These metaphors are not arbitrary. They follow consistent patterns shaped by physical sensation, cultural tradition, and medical theory.

Organs such as the heart, liver, gut, and skin do more than sustain life. Rather, they become instruments of emotional meaning. Through them, we express courage, fear, grief, and joy in terms that feel physically grounded. Traditional Chinese Medicine, along with closely related systems such as Korean and Japanese traditional medicine, reinforces this connection, offering a systematized framework that often mirrors what idioms around the world have long expressed.

These bodily metaphors are not just colourful expressions. They reflect how cultures have historically explained the invisible forces of feeling through the visible structures of the body. By listening to how people describe their emotions, we gain insight into how anatomy, language, and medical thought converge.

Recognizing these metaphors is more than a linguistic exercise. It is a path toward deeper empathy, cross-cultural understanding, and a more holistic view of what it means to feel.

- Ariel Kim, R.Ac, R.TCMP, Ph.D.