By Mayo Clinic Staff
A high white blood cell count is an increase in disease-fighting cells in your blood.
The exact threshold for a high white blood cell count varies from one laboratory to another. In general, for adults a count of more than 11,000 white blood cells (leukocytes) in a microliter of blood is considered a high white blood cell count.
A high white blood cell count is also called leukocytosis.
A high white blood cell count is usually found when your doctor orders tests to help diagnose a condition you're already experiencing. It's rarely an unexpected finding or simply discovered by chance.
Talk to your doctor about what these results mean. A high white blood cell count, along with results from other tests, might already indicate the cause of your illness. Or your doctor may suggest other tests to further evaluate your condition.
Dec. 17, 2015
- Cerny J, et al. Why does my patient have leukocytosis? Hematology Oncology Clinics of North America. 2012;26:303.
- McPherson RA, et al. Leukocytic disorders. In: Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa.: Saunders Elsevier; 2011. Accessed Oct. 6, 2015.