What is the term for the increase in the number of leukocytes in response to infection?

Leukocytosis is the term used to describe an increase in the number of leukocytes (white blood cells) in the bloodstream, which typically occurs as a physiological response to infection or inflammation. When the body detects an infection or the presence of pathogens, the immune system activates and stimulates the production of more leukocytes. These cells play a crucial role in the body's defense mechanisms, helping to identify and eliminate infectious agents.

Increased leukocyte counts are often used as a clinical marker to diagnose infections, as certain types of leukocytes can indicate different infectious processes. For example, an elevation in neutrophils typically suggests a bacterial infection, while an increase in lymphocytes may indicate a viral infection.

Other terms related to blood cell counts differ from leukocytosis in meaning. Leukopenia refers to a reduction in white blood cell count, typically indicating a compromised immune response. Hemolysis involves the breakdown of red blood cells, which can lead to anemia. Thrombocytosis denotes an increase in platelet count, which can be associated with various medical conditions but does not pertain to leukocyte levels or responses to infections. Understanding these terms and their implications is essential for diagnosing and responding to various clinical situations.