A White Blood Cell (WBC) differential breaks your white blood cells into different types and shows how many of each you have.
It’s often reported along with a WBC count as part of a Complete Blood Count (CBC).
This test looks at the percentage and number of different white blood cells, including:
Neutrophils – respond to infection and stress
Lymphocytes – support immune memory and defense
Monocytes – help clean up infections
Eosinophils – involved in allergies and parasites
Basophils – involved in inflammation and allergic response
Each type has a different role in the immune system.
Each white blood cell type has its own reference range.
Your lab report will show:
Percentages
Absolute counts
Reference ranges for each
Small shifts are very common.
A higher level of a specific white blood cell may reflect:
Infection or inflammation
Allergies or asthma
Stress or physical exertion
Recovery from illness
The pattern matters more than one value.
Lower levels may be linked to:
Viral infections
Medications
Temporary immune suppression
Normal variation
Many mild decreases are not concerning.
WBC differentials can change due to:
Recent illness
Stress or lack of sleep
Allergies
Lab timing
Results often return to normal on their own.
Doctors may repeat this test if:
Several values are abnormal
Symptoms are present
They want to monitor immune trends
Looking at changes over time is often more helpful.
An abnormal WBC differential does not automatically mean something serious.
Doctors usually interpret it together with:
Total WBC count
Symptoms
Other lab results
A WBC differential shows how your immune system is responding.
Most changes are temporary, explainable, and not dangerous.
You may want to read:
White Blood Cell Count (WBC) Explained
Complete Blood Count (CBC) Explained
Platelet Count Explained
You can also use the navigation bar above to explore other blood test results.
This information is for educational purposes only and is not medical advice. Always talk with a healthcare professional about your results.