What Are the Causes of High White Blood Cell Count?
Jun 06, 2019
Source: Cainiu Health
Dr. Xing Jian
Introduction
An elevated white blood cell (WBC) count in clinical practice—such as in cases associated with fever—may indicate infection. However, an increased WBC count does not necessarily signify infection or inflammation; it can also occur under stress conditions—for example, after vigorous exercise or during states of fear or anxiety.
1. Infection
An elevated white blood cell (WBC) count in clinical practice—especially when accompanied by fever—often suggests an infectious process. This is commonly referred to as an inflammatory response, which clinically manifests primarily through two key signs: first, an increased WBC count; and second, fever.
2. Stress Response
However, an elevated WBC count does not necessarily indicate infection or inflammation. For instance, physiological stress—such as vigorous exercise, intense fear, or severe anxiety—can also trigger a transient, stress-induced leukocytosis. Nevertheless, in clinical settings, WBC elevation is most commonly associated with inflammatory responses.
Differentiating Types of Infection:
To differentiate infection types and determine etiology, consider the following: In bacterial infections, the total WBC count typically increases. WBCs are further classified into subtypes—including neutrophils, lymphocytes, eosinophils, basophils, and monocytes.
Clinically, neutrophils and lymphocytes are most frequently assessed. In bacterial infections, both the total WBC count and the neutrophil percentage are typically elevated. Conversely, in most viral infections, the total WBC count decreases, with reduced neutrophil proportion and a relative increase in lymphocyte percentage.
