Monocyte Count (Peripheral Blood)

What Is a Monocyte Count Used For?

Doctors may order this test to check for infections, autoimmune diseases, or conditions affecting your immune system, such as leukemia or certain inflammatory disorders. It can also help monitor treatment responses, like chemotherapy or long-term medications that affect white blood cells.

When Might You Need This Test?

You might need a monocyte count if you have symptoms like frequent infections, unexplained fevers, fatigue, or swelling in joints/skin. It’s also part of routine blood work for people with chronic illnesses or those undergoing cancer treatment.

How Is the Test Performed?

A small blood sample is taken from a vein (usually in your arm). The sample is sent to a lab where machines count and identify different types of white blood cells, including monocytes. No special preparation is needed.

What Do Results Mean?

Results show the number of monocytes in your blood. High levels may suggest infection, inflammation, or certain cancers. Low levels could indicate immune suppression, bone marrow disorders, or medications that affect white blood cells. Your doctor will interpret results in the context of your overall health.