White blood cell 12.77 should be a white blood cell count of 12.77×10^9/L, which is already above the normal range and abnormal. Normal human white blood cells should be (4.0~10.0)x10^9/L. Causes of high white blood cells include physiological factors, bacterial infections, hemorrhage, leukemia and so on. 1. Physiological factors: common in strenuous exercise, menstruation, ovulation, late night, etc. Usually no treatment is needed, after removing these factors, the white blood cell value will return to normal. 2. Bacterial infections: such as fever, tonsillitis, inflammatory reactions in the body, etc., can lead to elevated white blood cells, accompanied by elevated neutrophils. 3. Bleeding: such as gastrointestinal bleeding, traumatic bleeding, etc., can lead to a temporary increase in white blood cells, which is the body’s stress response. When the bleeding is controlled and the vital signs return to stable, the white blood cells will slowly return to normal. 4. Leukemia: It is mainly because of the abnormal proliferation of bone marrow, unrestricted proliferation of blood cells, and released to the peripheral blood, while the normal hematopoietic cells are inhibited, so there will be typical leukemia blood changes and symptoms. There are many reasons leading to the elevation of white blood cells, which can not be judged simply based on blood routine, but need to be combined with the patient’s clinical symptoms and other test results for a comprehensive analysis, and can not be blindly jumped to conclusions, but must be consulted with a doctor and diagnosed under the guidance of the doctor’s condition.