1Blood — the red liquid that circulates through the body, carrying oxygen and nutrients.
指を切って血が出た。
I cut my finger and it started bleeding.
毎年、献血に協力している。
I donate blood every year.
医者は血のサンプルを検査に回した。
The doctor sent a blood sample for testing.
2Refers to blood ties or family lineage, as in "to inherit someone's bloodline."
彼女には芸術家の血が流れている。
She has an artist's blood running through her veins.
その一族は代々医者の血を受け継いでいる。
That family has passed down a lineage of doctors for generations.
彼は父親の血を濃く受け継いだようだ。
He seems to have strongly inherited his father's bloodline (traits).
3A figurative use referring to stirred-up feelings or passion, as in expressions like "the blood stirs."
応援席の熱気に、選手たちの血が騒いだ。
The heated atmosphere from the cheering section stirred the players' blood.
久しぶりの試合に、彼の血が騒いでいるのが分かった。
You could tell his blood was stirring with excitement over the match after so long.