What term is defined as an increase in the number of white blood cells?

The term that describes an increase in the number of white blood cells is leukocytosis. This condition indicates that the body is responding to an underlying issue, such as infection, inflammation, stress, or more serious conditions like leukemia. The elevation in white blood cells is a crucial indicator for clinicians, as it often signifies that the immune system is actively engaged in combating a problem.

Other terms, while they relate to blood cells, denote different conditions: leukopenia refers to a decrease in white blood cells, thrombocytosis denotes an increase in platelets, and pancytopenia signifies a reduction in red blood cells, white blood cells, and platelets simultaneously. Understanding these terms is essential for accurately interpreting laboratory results and diagnosing various hematological conditions.