Blood loss 1000ml first to clarify the cause of blood loss, if it is a daily blood donation, 200ml, 400ml is more common, after donating blood slightly dizziness, the 2nd-3rd day can be recovered naturally, will not cause any discomfort. If the blood loss is 1000ml, we have to judge whether it has caused the patient’s blood volume to be insufficient, exceeding the compensatory function, or even causing shock, etc. The patient manifests decreased cardiac output, decreased blood pressure, pallor, etc., and needs active treatment, because insufficient blood volume will lead to the obstacle of blood supply and oxygenation of important organs, such as the heart and the brain, and will cause the corresponding symptoms. Therefore, the patient’s hematocrit should also be checked at this time, and if the hematocrit decreases to a certain degree, the blood volume should be supplemented in time, and the nutritional aspect should also be supplemented. If the patient actively treats the primary disease, such as surgery, timely supplementation of blood volume, timely nutrition, usually about 1 month can be recovered. Therefore, for this situation of excessive blood loss, because of its complexity, some physiological, surgery-induced to see the corresponding hematocrit index, clinical cardiopulmonary, cardio-cerebral perfusion index.