Understanding Lab Tests for Severe Infection
Written by Private MD Labs Medical Writing Team • Last Updated: September 8, 2025
A severe infection occurs when harmful microorganisms like bacteria, viruses, or fungi overwhelm the body's immune defenses, potentially leading to serious complications. Blood tests play a crucial role in diagnosing infections, assessing their severity, and monitoring the body's immune response.
Recommended Test
White Blood Cell Count (WBC)
This test measures the number of white blood cells in your blood, which are the primary defenders of your immune system. A very low WBC count can indicate a severe infection that is overwhelming the immune system, suggesting that the body's ability to fight the infection may be compromised and immediate medical attention is required.
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Why Blood Testing is Essential for Severe Infections
While the source of infection may be identified through various methods, blood tests provide critical information about how the body is responding to the infectious agent. These tests can reveal whether the immune system is fighting effectively or if it's being overwhelmed, helping healthcare providers determine the appropriate treatment approach and monitor progress.
Understanding Your Results
White blood cell counts can vary during infections - they may be elevated as the body fights the infection, or dangerously low if the infection is severe enough to overwhelm the immune system. A healthcare provider will interpret these results in the context of your symptoms and overall clinical picture to determine the best treatment approach.
Important Considerations
The information here is for educational purposes only and is not a substitute for professional medical advice. Always consult with a healthcare provider for diagnosis and treatment.
