Absolute Lymphocyte Count (Whole Blood)

What Is a Lymphocyte Count Used For?

Doctors use this test to diagnose or monitor conditions affecting the immune system, such as infections, autoimmune diseases, or blood disorders. It may also be checked during cancer treatment to assess how well your body is responding to treatment or to detect side effects like immunosuppression.

How Is This Test Performed?

A small blood sample is drawn from a vein, usually in your arm. The blood is then analyzed to count the number of lymphocytes. No special preparation is needed, but fasting may be required depending on your specific test order.

What Are Common Reasons for Testing?

Your doctor might order this test if you have symptoms like frequent infections, fatigue, swelling, or unexplained weight loss. It can also be used to evaluate immune function before or after treatments like chemotherapy or organ transplants.

What Do Results Mean?

Results are typically reported as a count of lymphocytes per microliter (µL) of blood. While reference ranges vary by lab, lower-than-expected counts may indicate immune suppression, while higher-than-expected counts could signal conditions like chronic infections or certain cancers.