haem(o)- Also haema- and haemat(o)-.
[Greek haima, haimat-, blood.]
Many medical terms contain these forms; in the US, they all begin hem-. A few examples of haemo-: haemorrhage (Greek rhēgnunai, burst), a profuse escape of blood from a ruptured blood vessel; haemoglobin, a red protein responsible for transporting oxygen in the blood, of which the iron-containing part is the haem (US heme); haemophilia (Greek philia, fondness or undue inclination), a medical condition in which the blood does not clot properly.
The longer form haemato- is found in haematocrit (Greek kritēs, judge), the ratio of the volume of red blood cells to the total volume of blood, or an instrument for measuring this; haematemesis (Greek emesis, vomiting) is vomiting of blood; haematuria is the presence of blood in urine.
The important ore of iron called haematite was so named - from Greek haimatitēs (lithos), blood-like (stone)—because it is a reddish-black mineral.
See also sangui-.