High white blood cell count is an increase in disease-fighting cells (leukocytes) circulating in your blood. High white blood cell count is also called leukocytosis.

The threshold for high white blood cell count varies from one medical practice to another. A count of more than 11,000 leukocytes in a microliter of blood in adults is generally considered a high white blood cell count. The threshold for a high white blood cell count in children varies with age and size.

A high white blood cell count is usually found when your doctor has ordered 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 and results from other tests may already indicate the cause of your illness, or your doctor may suggest other tests to further evaluate your condition.

Dec. 14, 2012