Neutrophil count (absolute, serum/plasma)

What Neutrophils Do in Your Body

Neutrophils are a critical part of your immune system. They rush to infection sites to destroy bacteria and other harmful invaders. When your body detects an infection, neutrophil levels often rise to help clear the threat. This test helps doctors assess whether your immune response is functioning properly or if there may be an underlying issue.

When This Test Might Be Ordered

Your doctor may recommend this test if you have symptoms like frequent infections, unexplained fevers, or signs of inflammation. It’s also used to monitor conditions like leukemia, autoimmune diseases, or after treatments that affect the immune system.

What to Expect Before the Test

No special preparation is needed for this blood test. You’ll have a small needle inserted into your arm or hand to draw a blood sample. The process usually takes a few minutes, and you may feel a brief pinch. If you’re on blood thinners, let your doctor know before the test.

What the Results Mean

Results are reported as the number of neutrophils per microliter (µL) of blood. Very low levels may indicate immune deficiencies or bone marrow disorders, while very high levels could suggest infections, inflammation, or other conditions. Your doctor will interpret the results in the context of your overall health and symptoms.