What is the medical term for an increase in white blood cells?

Leukocytosis is the medical term that refers to an increase in the number of white blood cells (leukocytes) in the bloodstream. This elevation often occurs as a response to various conditions, such as infections, inflammation, stress, or certain diseases like leukemia. The increase in white blood cells is a crucial part of the body's immune response, helping to fight off pathogens and other foreign substances.

In contrast, leukopenia denotes a decrease in white blood cells, which can lead to increased susceptibility to infections. Anemia pertains to a deficiency in red blood cells or hemoglobin, resulting in reduced oxygen transport in the body. Polycythemia refers to an increase in red blood cells and is not related to white blood cell counts at all. Understanding these terms is essential for recognizing different medical conditions and their implications for patient health.