Blood levels and their effects
Our system assumes that an individual with full blood volume intact has 6 litres of blood.
Lost some blood - the patient has lost up to 0.9 litres of blood. The patient does not suffer significantly from the blood loss itself.
Lost a lot of blood - the patient has lost between 1 and 1.8 litres of blood. Should the patient bleed and/or fall unconscious, the blood loss might prevent reawakening.
Lost a large amount of blood - the patient has lost between 1.9 and 2.4 litres of blood, and it is unlikely that the patient is conscious at this point. The patient will not reawaken despite efforts from medics until blood volume is restored. In case of cardiac arrest, resuscitation is possible but difficult.
Lost a fatal amount of blood - the patient has lost more than 2.4 litres of blood, and is likely to suffer cardiac arrest due to blood loss. Resuscitation is impossible until blood volume is at least partially restored.
