Macrophages, Body Fluid, Manual Count

What This Test Measures

A laboratory professional examines a prepared slide of your body fluid under a microscope and counts the macrophages present. Macrophages are a type of white blood cell that engulf and break down debris, microbes, and other particles. The result is usually reported as part of a white blood cell differential for the fluid.

Why It May Be Ordered

Your healthcare provider may order this test when fluid has collected in a body cavity, such as the chest, abdomen, or around the heart or joints, and they want to understand what kind of cells are present. The macrophage count can support evaluation of inflammation, infection, or other causes of fluid buildup.

How the Sample Is Collected

A small sample of the fluid is collected by a procedure your provider performs, such as a needle draw from the affected area. The sample is sent to the laboratory, where it is prepared and reviewed manually. Your provider will explain the collection procedure and any preparation needed.

What the Results Mean

Results are interpreted together with other findings from the same fluid sample and with your symptoms, imaging, and history. No single cell count gives a diagnosis on its own, so your provider will explain what the findings mean for your situation.