Certified Medical-Surgical Registered Nurse Practice Test 2025 - Free Practice Questions and Study Guide

An elevated white blood cell count (WBC) is a key indicator of infection. White blood cells are essential components of the immune system, primarily involved in defending the body against pathogens such as bacteria, viruses, and fungi. When an infection occurs, the body responds by increasing the production of WBCs to help combat the invading organisms. Thus, an elevated WBC count often suggests that the body is actively fighting an infection or, in some cases, may point to other inflammatory responses.

Low blood sugar levels, high potassium levels, and decreased hemoglobin levels can indicate various medical conditions but are not specific indicators of infection. Low blood sugar may suggest issues like diabetes management or metabolic problems, whereas high potassium levels can be associated with kidney dysfunction or tissue damage. Decreased hemoglobin levels commonly relate to anemia or blood loss but do not directly indicate the presence of an infection. Therefore, of the choices provided, an elevated WBC count is the most relevant marker for detecting a potential infection.