What is this test?
This test reports the main types of white blood cells, such as neutrophils, lymphocytes, monocytes, eosinophils and basophils. Their pattern can help assess infection, inflammation, allergy and blood-cell disorders.
Why might it be ordered?
- To investigate an abnormal total white-cell count or symptoms of infection or inflammation.
- To monitor a condition or treatment that can alter immune cells.
What sample is needed?
A blood sample is required. The laboratory chooses the correct tube and handles the sample for this test.
How should you prepare?
Fasting is usually unnecessary. Recent exercise, stress, infection and some medicines can affect the pattern.
How should you understand the result?
Both percentages and absolute counts matter. No single white-cell pattern is specific enough to diagnose an infection, allergy or blood disorder without other evidence.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.