Lowered white blood cells have many causes and should not be equated with leukemia.
The normal leukocyte count is 4×10/L-10×10/L, and may vary slightly depending on the testing facility and the test method. The normal range of normal values may vary depending on the testing facility and the method. The usual definition of leukopenia is below 4×10/L. There are many causes of leukopenia, including infectious diseases, especially viral infections, and certain bacterial infections such as S. typhi or chronic diseases of old age and frailty.
Other causes include hematologic disorders (such as certain types of anemia, some types of leukemia, malignant histiocytosis, etc.), physicochemical radiation, side effects of certain medications (such as certain thyroid medications, diabetes medications, antibiotics, antipyretics, etc.), autoimmune disorders, and other causes of hypocellularity. Therefore, hypocellularity cannot be simply equated with leukemia.