Macrophages, Body Fluid, Manual Count

What This Test Measures

Macrophages are large white blood cells that engulf and digest debris, microbes, and other particles. In body fluids, their numbers and appearance can rise when there is inflammation, infection, or bleeding. This test uses a manual count, meaning a laboratory professional examines the fluid under a microscope rather than relying only on an automated instrument.

Why Your Provider May Order It

Your provider may order a body fluid macrophage count when imaging or symptoms suggest fluid accumulation in a cavity, such as around the lungs or in the abdomen. The result is usually interpreted alongside other cell counts, protein levels, and fluid appearance to help distinguish between conditions like infection, inflammation, or malignancy.

How the Sample Is Collected

A body fluid sample is typically collected by a clinician using a needle or catheter, depending on the fluid space involved. The fluid is sent to the laboratory, where it is prepared and examined under a microscope. Collection methods vary, so follow the instructions given by your care team.

What the Results Mean

A manual count reports how many macrophages are seen, often as a proportion of the total white cells. Higher or lower numbers are not interpreted alone; they are compared with other findings in the same fluid and with your symptoms. Your provider will explain what your specific result means in context. No single numeric range applies to every fluid type, so ask your care team about your report.