acute posthemorrhagic anemia acute posthemorrhagic anemia acute posthemorrhagic anemia or acute blood loss anemia is a condition in which a person quickly loses a large volume of circulating hemoglobin. acute blood loss is usually associated with an incident of trauma or a severe injury resulting in a large loss of blood. it can also occur during or after a surgical procedure. acute posthemorrhagic anemiaother namesacute blood loss anemiaspecialtyemergency medicine