Leukocyte (White Blood Cell) Fraction Percentage by Differential Count is a test that measures the relative percentage of each type of white blood cell in your blood to help assess your immune health.

Why This Test Is Done: Your doctor may recommend this test to look into symptoms or monitor your health, as it helps reveal how your immune system is responding to potential issues.

Doctors may order this test to evaluate symptoms such as frequent infections, unexplained fevers, fatigue, or signs of immune system dysfunction. It can also be part of routine blood work or monitoring for conditions like leukemia, autoimmune diseases, or chronic infections, helping to track changes over time.

What to Expect Before the Test: There is usually no special preparation required, and you can go about your day normally before having your blood drawn for this simple laboratory test.

No special preparation is needed. A simple blood draw from your arm is all that’s required. The test is typically done in a lab setting and results are usually available within a few days, allowing your doctor to review them with you promptly.

How the Test Works: A trained professional collects a small blood sample which is then examined in the laboratory to count the different white blood cell types and their relative percentages.

A small sample of blood is taken and analyzed under a microscope to count and identify the different types of white blood cells (neutrophils, lymphocytes, monocytes, eosinophils, and basophils). Each type is then expressed as a percentage of the total white blood cell count, giving a detailed differential profile.

Possible Results and Interpretation: Your results will show the percentages of each cell type, and your doctor will explain what any high or low values might mean for your overall health and wellbeing.

While specific percentages can vary based on health status, an abnormal differential may indicate an infection, allergy, or other underlying conditions. Your doctor will interpret results in the context of your overall health and symptoms to provide a clear plan.