WBC test, or white blood cell count, is a common laboratory test that measures the number of white blood cells in a sample of blood. White blood cells are crucial components of the immune system, helping the body fight infections and respond to inflammation. Abnormal WBC test results-either elevated or decreased-can signal infection, inflammatory or autoimmune disorders, bone marrow disease, medication effects, or certain cancers such as leukemia. Because white blood cell abnormalities may indicate serious underlying conditions, insurers pay close attention to WBC test results as part of routine underwriting lab panels.

Underwriters review WBC test results alongside differential counts and other labs to assess overall health and to identify potential red flags that warrant further investigation. Mild, transient elevations associated with minor infections are usually not concerning, while persistent, significantly abnormal counts may prompt requests for additional records, specialist evaluations, or postponement. Advisors may need to help clients obtain follow-up lab work or physician explanations when WBC anomalies appear unexpectedly. Understanding WBC test results enables advisors to interpret lab summaries more effectively, reassure clients when variations are benign, and prepare them for potential underwriting questions when results fall outside normal ranges.