Definition

Granulocytes are a type of white blood cell that has small granules inside them. These granules contain proteins. The specific types of granulocytes are neutrophils, eosinophils, and basophils.

Granulocytes, specifically neutrophils, help the body fight bacterial infections. The number of granulocytes in the body usually increases when there is a serious infection. People with a lower number of granulocytes are more likely to develop serious infections.

Granulocytes are counted as part of a white blood cell differential test.

References

Hall JE. Hall ME. Resistance of the body to infection: I. leukocytes, granulocytes, the monocyte-macrophage system, and inflammation. In: Hall JE, Hall ME, eds. Guyton and Hall Textbook of Medical Physiology. 14th ed. Philadelphia, PA: Elsevier; 2021:chap 34.