Physiology · Blood

Blood volume and regulation

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Definition

  • Blood volume is the total volume of blood (cells plus plasma) in the circulatory system; blood is a liquid connective tissue filling the heart and blood vessels.

Adult blood volume5 to 6 liters, about 8% of body weight

Normal Blood Volume

Normal blood volume

Group

Adult male

Blood volume
5 to 6 liters

Adult female

Blood volume
4.5 to 5.5 liters

Adult, per kg body weight

Blood volume
70 to 80 ml/kg

Children, per kg body weight

Blood volume
80 to 90 ml/kg

Per body surface area

Blood volume
2.8 liters/m2
  • Children have a lower absolute blood volume than adults, but a higher volume per kg body weight, since the value is expressed relative to their smaller body mass.