Classica Sinica Medica

八虚

bā xū

The eight emptinesses · ba xu

Also rendered: The eight hollows (plain, and it keeps the physical sense) · The eight empty places (clear, and 虚 is not quite emptiness) · The eight emptinesses (the site's convention, kept for the index)

Physiology

Reviewed · 2026-10-26

At a glance

Pinyin
bā xū
Simplified
八虚
Literal
八 bā — eight; 虚 xū — empty, hollow, the place where nothing is stored. Together: the eight hollows at the great joints, the places where the qi of the five depots passes and where evil lodges when it passes no further.
Shuowen
《說文》：虚，大丘也。从丘虍聲。引申爲空、爲不足。此篇以「虚」名八處，非虚實之虚，乃形體空闕之處，故下文云「皆機關之室，真氣之所過，血絡之所遊」。

In brief

The eight emptinesses are the two elbows, the two armpits, the two hips and the two backs of the knees — the hollows at the great joints. Huang Di asks what they answer to and Bo Gao answers in one word: the five depots. Each pair is the road by which one depot’s qi leaves when evil enters it — lung and heart to the elbows, liver to the armpits, spleen to the hips, kidney to the hollow behind the knee. The chapter then gives the reason for the name: 凡此八虚者，皆機關之室，真氣之所過，血絡之所遊 — they are the rooms of the mechanism, where true qi passes and blood vessels travel. Because they are rooms and not dead hollows, evil blood must not be allowed to stay: 住留則傷筋絡，骨節，機關，不得屈伸，故痀攣也. The eight are therefore both a map of where disease shows and a warning about what happens when it settles there.

Senses in the classical corpus

1
名目 人有八虚，各何以𠉀
人有八虛，各用以候什麼
A man has eight emptinesses — what does each of them serve to observe?
人有八虚 — 靈樞·邪客
2
所應 以𠉀五藏
用來診候五藏
They answer to the five depots — the whole of their diagnostic use.
以𠉀五藏 — 靈樞·邪客
3
部位 肺心有邪，其氣留於兩肘
肺心有了邪，其氣留在兩肘
Lung and heart: the qi stays at the two elbows; liver: the two armpits.
其氣留於兩肘 — 靈樞·邪客
4
所以然 皆機關之室，真氣之所過
都是關節的居室、真氣經過之處
They are the rooms of the mechanism, where true qi passes and blood vessels roam.
皆機關之室 — 靈樞·邪客
5
病變 住留則傷筋絡
邪氣血絡留止就傷筋絡
If they stay, the sinew networks are hurt and the joints will not bend: 痀攣.
住留則傷筋絡 — 靈樞·邪客

Occurrences in the classics

Passages where the term does real work, with the original, pinyin and English on the same line.

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1 passages
靈樞·邪客 Read in context →
黃帝問於歧伯曰：人有八虚，各何以𠉀？歧伯答曰：以𠉀五藏。黃帝曰：𠉀之奈何？歧伯曰：肺心有邪，其氣留於兩肘；肝有邪，其氣流于兩腋；脾有邪，其氣留于兩髀；腎有邪，其氣留于兩膕。凡此八虚者，皆機關之室，真氣之所過，血絡之所遊，邪氣惡血，固不得住留，住留則傷筋絡，骨節，機關，不得屈伸，故痀攣也。 黄帝问于歧伯曰：人有八虚，各何以𠉀？歧伯答曰：以𠉀五藏。黄帝曰：𠉀之奈何？歧伯曰：肺心有邪，其气留于两肘；肝有邪，其气流于两腋；脾有邪，其气留于两髀；肾有邪，其气留于两腘。凡此八虚者，皆机关之室，真气之所过，血络之所游，邪气恶血，固不得住留，住留则伤筋络，骨节，机关，不得屈伸，故痀挛也。
Huáng Dì wèn yú Qí Bó yuē: rén yǒu bā xū, gè hé yǐ hòu? Qí Bó dá yuē: yǐ hòu wǔ zàng. Huáng Dì yuē: hòu zhī nài hé? Qí Bó yuē: fèi xīn yǒu xié, qí qì liú yú liǎng zhǒu; gān yǒu xié, qí qì liú yú liǎng yè; pí yǒu xié, qí qì liú yú liǎng bì; shèn yǒu xié, qí qì liú yú liǎng guó. fán cǐ bā xū zhě, jiē jī guān zhī shì, zhēn qì zhī suǒ guò, xuè luò zhī suǒ yóu, xié qì è xuè, gù bù dé zhù liú, zhù liú zé shāng jīn luò, gǔ jié, jī guān, bù dé qū shēn, gù gōu luán yě.
The Emperor asked Qi Bo: Man has eight hollows — how is each of them examined? Qi Bo answered: They are examined for the five viscera. The Emperor said: How are they examined? Qi Bo said: When lung and heart have evil, its qi stays at the two elbows; when the liver has evil, its qi flows to the two armpits; when the spleen has evil, its qi stays at the two thighs; when the kidney has evil, its qi stays at the two backs of the knees. All these eight hollows are chambers of the joints, where true qi passes and the blood network vessels roam. Evil qi and bad blood certainly may not stay there; if they stay they injure the sinew network, the bones and the joints, so that they cannot bend and stretch — hence hooking and contracture.
「八虚」本篇2見，黃帝問八虚何以候，伯高答以候五藏，末言機關之室、血絡所遊，名義與病變俱備，故引五段。

Compounds built on this term

兩肘
liǎng zhǒu
the two elbows
肺心之邪所留
兩髀
liǎng bì
the two hips
脾之邪所留
兩膕
liǎng guó
the two backs of the knees
腎之邪所留

How it has been translated

Every rendering below is a decision about which reader is being addressed. There is no neutral option.

This sitethe eight emptinessesthe set as a name
Literaleight hollowsexact, and it reads as anatomy only
Clinicalthe eight joint hollows of the five depotsclear, and it explains the map

Entry status

Review pending — who reviews this?

2026-10-26

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Reading path

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