Leukocytes 50×10⁹/L in the blood is very serious. The normal value of leukocytes is (4~10)×10⁹/L. Leukocytes 50×10⁹/L indicates a significant increase in leukocytes, and causes of significant increase in leukocytes include leukemia, sepsis, adult Steele’s disease and so on. 1. Leukemia: the main clinical manifestations are anemia, bleeding, fever with infection, as well as enlarged liver, spleen, lymph nodes and bone pain. Severe acute leukemia invades the central nervous system, there will be headache, vomiting, strong collar, optic papilla edema and other symptoms of increased intracranial pressure, and the condition is critical. 2. Septicemia: septicemia is a systemic inflammatory response syndrome, if not actively treated, the condition continues to progress, and in severe cases, it can lead to septic shock, systemic organ failure, unstable vital signs, and life-threatening. Therapeutic drugs include levofloxacin, cefoperazone and so on. 3. Adult Steele’s disease: blood routine can be manifested as an increase in the total number of peripheral blood leukocytes, mainly manifested as fever, arthralgia, rash, myalgia, enlarged lymph nodes, and in severe cases, with systemic damages, such as secondary infections and hepatic failure, which is easy to be life-threatening. Leukocytes 50×10⁹ / L suggests that the condition is serious, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, under the guidance of physicians to give targeted treatment or treatment.