Granulocyte count (absolute)

What Is a Granulocyte Count?

Granulocytes are a subset of white blood cells (leukocytes) that include neutrophils, eosinophils, and basophils. They play a critical role in immune responses, particularly against bacterial and fungal infections. An absolute granulocyte count helps doctors assess your ability to fight infections, especially in cases where other white blood cell counts (like total white blood cell count) may not be informative enough.

Why Might You Need This Test?

Your doctor may order this test if you have symptoms of infection (such as fever, fatigue, or swelling), if you’re undergoing treatment for conditions that affect white blood cells (like chemotherapy, autoimmune diseases, or certain cancers), or if you have a known risk for infections due to conditions like diabetes or kidney disease. It can also be used to monitor treatment effectiveness or side effects of medications.

How Is the Test Performed?

A small sample of blood is drawn from a vein, usually in your arm. The blood is then analyzed in a lab to count the number of granulocytes. This is typically done using automated blood cell counters or specialized laboratory techniques.

What Do the Results Mean?

Results are usually reported as a count of granulocytes per microliter (µL) of blood. While specific reference ranges can vary by lab, very low counts (below normal) may indicate conditions like bone marrow disorders, severe infections, or certain medications that suppress white blood cells. Very high counts may suggest chronic inflammation, infections, or other immune-related conditions.