Suddenly high and low white blood cells may be due to infection, drug effects, autoimmune disease and other factors, need to be analyzed. 1. Infection: white blood cells suddenly high and suddenly low may be due to a recent pathogen infection, resulting in neutrophils, lymphocytes and other white blood cells rise briefly, until the disease is cured after the white blood cells and down. 2. Drugs: some drugs such as glucocorticoids can lead to the phenomenon of elevated white blood cells, because glucocorticoids will promote the proliferation of white blood cells, leading to an increase in the number of white blood cells, to be no longer use hormones after the white blood cells may return to normal, that is, resulting in the emergence of white blood cells suddenly high and suddenly low. 3. Autoimmune disease: some autoimmune diseases will destroy white blood cells, such as systemic lupus erythematosus patients in the body neutrophils in the blood and spleen will destroy too much, resulting in a decrease in white blood cells, to be recovered from the disease after the white blood cells rose to normal. There are many other reasons for the sudden high and low white blood cells, such as leukemia, etc. It is recommended that once a similar situation occurs, consult a doctor in time and take targeted measures under the guidance of the doctor.