Meaning
The kanji 血 means blood — the vital red fluid that circulates through the body and sustains life. Its form traces directly back to an ancient pictograph. In oracle bone script and early Chinese writing, 血 depicted a ritual ceremonial bowl or vessel (皿) with a mark inside representing a drop of blood. This image comes from ancient religious practices in which blood was offered in sacred vessels during ceremonies and oaths.
Beyond its literal, physical meaning, 血 runs deep in the figurative language of Japanese. It expresses the bonds of family and ancestry — the idea that people who share blood share a fundamental connection. You will find it in words for lineage, heritage, and kinship. It also appears in expressions describing passion and raw emotion, such as 血が騒ぐ (chi ga sawagu), meaning "the blood stirs" — used when someone feels excitement or fighting spirit rising within them.
With 6 strokes, 血 is a Grade 6 kanji in Japan's elementary school curriculum. It serves as its own radical (部首, ぶしゅ), known as the chi-hen or ketsu-radical. Although relatively few compound characters are built from it as a radical, the kanji itself appears throughout medical, biological, and everyday Japanese vocabulary.
Readings
On'yomi (音読み) — Chinese-derived readings
The on'yomi reading of 血 is ケツ (KETSU). This reading originates from the ancient Chinese pronunciation and is used in most formal and compound vocabulary (熟語, じゅくご), particularly in medical, scientific, and academic contexts. When you encounter 血 as part of a longer compound word — especially in a hospital, textbook, or formal document — it almost certainly uses the ケツ reading.
One phonetic note worth knowing: when 血 appears before voiceless consonants like k or s in a compound, the vowel often doubles to create a geminate consonant (っ), as in 血管 (kekkan). This natural sound change in Japanese is called sokuon assimilation.
- 血液 (ketsueki) — blood (as a liquid substance, used in medical settings)
- 血管 (kekkan) — blood vessel
- 血圧 (ketsuatsu) — blood pressure
- 出血 (shukketsu) — bleeding, hemorrhage
- 献血 (kenketsu) — blood donation
- 輸血 (yuketsu) — blood transfusion
- 貧血 (hinketsu) — anemia (literally "poor blood")
Kun'yomi (訓読み) — Native Japanese readings
The kun'yomi reading is ち (chi). This is the native Japanese word for blood, predating the introduction of Chinese characters. It is used in everyday speech, colloquial expressions, and native Japanese compound words. You will most often hear ち when someone is talking about visible blood from a wound, a nosebleed, or in emotionally expressive contexts. When ち follows certain sounds in a compound, it undergoes rendaku (voiced consonant shift) and becomes ぢ, as in 鼻血 (hanaji).
- 血 (chi) — blood (standalone word in everyday speech)
- 鼻血 (hanaji) — nosebleed (ち → ぢ via rendaku)
- 血まみれ (chimamire) — covered in blood, bloodstained
- 血筋 (chisuji) — bloodline, lineage
- 血縁 (ketsuen) — blood relation, kinship (standard reading; the kun reading ちえん exists but is rare and seldom used in modern Japanese)
Common Words & Compounds
Across medical, scientific, and social domains, 血 forms a wide range of essential vocabulary in Japanese.
Medical and Health Terms:
- 血液 (ketsueki) — blood (as a physiological substance)
- 血管 (kekkan) — blood vessel (artery or vein)
- 血圧 (ketsuatsu) — blood pressure
- 血糖 (kettou) — blood sugar, blood glucose
- 血液型 (ketsuekigata) — blood type (A, B, O, AB)
- 出血 (shukketsu) — bleeding, hemorrhage
- 止血 (shiketsu) — stopping bleeding, hemostasis
- 輸血 (yuketsu) — blood transfusion
- 献血 (kenketsu) — blood donation
- 貧血 (hinketsu) — anemia
- 血色 (kesshoku) — complexion, healthy color of the face
Family, Lineage, and Figurative Uses:
- 血縁 (ketsuen) — blood relation, kinship
- 血統 (kettou) — bloodline, lineage, pedigree
- 血筋 (chisuji) — family line, ancestral bloodline
- 流血 (ryuuketsu) — bloodshed, effusion of blood
- 鼻血 (hanaji) — nosebleed
- 血まみれ (chimamire) — drenched in blood, bloodstained
Example Sentences
転んで膝から血が出た。
Koronde hiza kara chi ga deta.
I fell and blood came from my knee.
彼の血液型はA型です。
Kare no ketsuekigata wa ee-gata desu.
His blood type is A.
毎年、定期的に血圧を測っています。
Maitoshi, teikiteki ni ketsuatsu wo hakatte imasu.
Every year, I regularly have my blood pressure measured.
鼻血が止まらないので、病院へ行きました。
Hanaji ga tomaranai no de, byouin e ikimashita.
Since my nosebleed would not stop, I went to the hospital.
医者は血液検査を勧めました。
Isha wa ketsueki kensa wo susumemashita.
The doctor recommended a blood test.
彼女は去年、献血をしました。
Kanojo wa kyonen, kenketsu wo shimashita.
She donated blood last year.
貧血がひどくて、立ち上がれませんでした。
Hinketsu ga hidokute, tachiagaremasendeshita.
My anemia was so bad that I could not stand up.
事故で大量の出血があったが、命は助かった。
Jiko de tairyou no shukketsu ga atta ga, inochi wa tasukatta.
There was a large amount of bleeding in the accident, but the person survived.
彼らに血縁関係はないが、本当の兄弟のように仲がいい。
Karera ni ketsuen kankei wa nai ga, hontou no kyoudai no you ni naka ga ii.
They have no blood relation, but they get along like true brothers.
血は水よりも濃いというが、本当にそう思う。
Chi wa mizu yori mo koi to iu ga, hontou ni sou omou.
They say blood is thicker than water, and I truly believe it.
Memory Tip
Picture 血 as a dish or bowl (皿) with a single drop falling into it from above. This is exactly what the ancient pictograph showed: a ceremonial vessel used in sacred blood rituals. The horizontal strokes represent the rim and base of the bowl, while the vertical stroke with the inner mark shows the drop of blood settling inside. For the kun'yomi reading ち (chi), think of the English word chilly — the sight of blood gives many people a chilly feeling. You can also connect it to the Hán-Việt reading HUYẾT: Vietnamese words like huyết áp (blood pressure) and huyết thống (bloodline) share the same root and meaning.