Concept

Blood

血xue

2 sources

The red liquid that circulates within the vessels to moisten and nourish the body and support mental activity. The Neijing states that blood is formed when the middle jiao receives the essence of food and drink, extracts its fluid, and transforms it into a red substance; blood and qi are described as different in name but of the same kind, moving together to sustain life.

Source

Huangdi Neijing (Inner Canon of the Yellow Emperor)《灵枢·决气》（内经选读下篇·藏象·气血精神·原文2205）

References

《内经》论血散见多篇综合理解（决气/营卫生会/五藏生成等）
WHO IST-TCM 2022 术语对齐（WGM2# 225 Blood）

Full definition

Classical source text (Chinese) — English summary above.

中焦受氣取汁，變化而赤，是謂血

Citations

Huangdi Neijing (Inner Canon of the Yellow Emperor) · 托名黄帝/岐伯（先秦—西汉医家辑） · 《灵枢·决气》（内经选读下篇·藏象·气血精神·原文2205）Cited from Huangdi Neijing (Inner Canon of the Yellow Emperor) for its definition.
WHO international standard terminologies on traditional Chinese medicine · World Health Organization · WHO IST-TCM 2022, WGM2# 225 (§1.4 精气血津液类)Cited from WHO international standard terminologies on traditional Chinese medicine for its standardized terminology.