A high white blood cell count of 1045.50 x 10^9/L is very dangerous because a white blood cell count greater than 200 x 10^9/L is diagnostic of leukocytosis, which is a life-threatening condition that can lead to respiratory distress, intracranial hemorrhage, hypoxemia, slurred speech, and unresponsiveness, with a high risk of sudden death. When there is a high leukocyte 1045.50×10^9/L, a blood cell separator should be used urgently to remove the excessive leukocytes by single collection, and at the same time, primary treatment should be given to reduce the number of leukocytes, so as to avoid the risk. For example, patients with chronic granulocytic leukemia are treated with hydroxyurea and imatinib orally. The most common cause of leukocytosis is infection or leukemia, due to the abnormal proliferation of leukemia cells, released into the blood will lead to an abnormal increase in white blood cells, excessive white blood cells in the blood will consume a large amount of oxygen, and will cause the function of white blood cells and platelets to decrease, resulting in life-threatening symptoms such as respiratory distress, intracranial hemorrhage and other serious symptoms. When the white blood cells are 1045.50 x 10^9/L, it is very dangerous and requires urgent therapeutic measures under the guidance of a physician.