yellow blood; blood low in blood cells
Dated term for blood that appears yellowish due to low red blood cell count, historically associated with frequent blood donation. Now rarely used; modern medical contexts prefer more precise terms.
It used to be said that repeated blood donations would turn your blood into 'yellow blood'.
Compound of 黄色い (yellow) and 血 (blood), literally 'yellow blood'. The term arose from the observation that frequent blood donation could lead to blood with a yellowish tint due to reduced red blood cells.