White Blood Cell Count (Leukocytes)
|Why is this test done?||White blood cell count is part of a complete blood count. The test results are used to assess the production of blood cells or to identify various imbalances, such as infections, inflammation, immune system disorders, etc. It can also be part of drug management in people taking certain drugs.|
|How to prepare:||
|Associated Tests:||In addition to white blood cell count, the complete blood count also measures several other parameters such as hemoglobin, hematocrit, red blood cells physical characteristics and count, platelet count and differential white blood cell count.|
White blood cells (leukocytes) are cells of the immune system found in the blood and lymph. Their role is to defend the body. There are five types of leukocytes: neutrophils, eosinophils, basophils, lymphocytes and monocytes. Each type plays a specific role in the body. Leukocytes are produced in the bone marrow.
What does an abnormal test result mean?
If the result is too high (leukocytosis)
White blood cell count can be elevated due to an infection, trauma, shock, intoxication or major haemorrhage. Certain leukemias can also increase the leukocyte count.
If the result is too low (leukopenia)
Certain drugs that lessen the immune system, such as chemotherapy drugs, will reduce the amount of white cells in the blood. It's also true of certain infections, anemias and leukemias.
Results cannot be interpreted by themselves. The results of other tests performed at the same time are important as well and are taken into consideration to determine the possible cause of any abnormal results.
Factors that can affect the result of the test
- White blood cell count increases at the end of pregnancy.
- Stress can also affect the leukocyte count.
- People who had their spleen removed can also have abnormal results.
- Certain drugs can lower the white blood cell count, such as:
- chemotherapy drugs;
- Immunosuppressant drugs (used by persons having undergone an organ transplant);
- clozapine (Clozaril™);
- certain antithyroid drugs, such as methimazole (Tapazole™);
- metronidazole (Flagyl™);
- quetiapine (Seroquel™).
What you need to know before the test
Before going for blood tests, a procedure or other exam, it is best to always bring a list of all the drugs you take (prescription, OTC and natural health products). Unless told otherwise, you should take your medication as usual on the day of the test. When in doubt, ask your pharmacist for more information.
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.