Leukocytes (White Blood Cells) – Your Immune Defense Marker
Leukocytes, commonly known as white blood cells (WBC), are the cornerstone of the immune system. They circulate in the blood and lymph, identifying and destroying pathogens such as bacteria, viruses, and parasites. The total leukocyte count is part of every complete blood count and is one of the first markers checked when infection or immune dysfunction is suspected.
Why Test Leukocytes?
A leukocyte count is essential for detecting infections, monitoring immune function, evaluating inflammatory conditions, and screening for blood cancers such as leukemia. It is included in routine health checks and is a frontline diagnostic tool.
What Do High Leukocytes Levels Mean?
Elevated white blood cells (leukocytosis) may indicate bacterial infection, inflammation, physical or emotional stress, smoking, allergic reactions, or blood disorders including leukemia.
What Do Low Leukocytes Levels Mean?
Low white blood cells (leukopenia) can result from viral infections, bone marrow failure, autoimmune diseases, chemotherapy, certain medications, or nutritional deficiencies affecting immune cell production.
Symptoms to Watch For
- Frequent or recurring infections
- Fever without obvious cause
- Fatigue and weakness
- Swollen lymph nodes
- Unexplained weight loss
- Easy bruising or bleeding
Who Should Get Tested?
- People with recurring or persistent infections
- Those with unexplained fever
- Patients undergoing chemotherapy or immunosuppressive treatment
- Anyone with suspected autoimmune disease
- Individuals undergoing routine health screening
How to Prepare for Your Test
No special preparation is required. Bring valid ID to your appointment.
Frequently Asked Questions
What is a normal white blood cell count?
What are the different types of leukocytes?
Can stress raise my white blood cell count?
Reviewed by
Wellth Team
Wellth
Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.
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The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.