What is absolute lymphocyte count?

The absolute lymphocyte count refers to the number of lymphocytes contained in a unit volume of the collected blood sample, typically expressed as the number of lymphocytes per liter of blood. The normal reference range is generally (0.8–4.0) × 10^9/L.

Lymphocytes are an important type of immune-active cells in the human body. The absolute lymphocyte count serves as a significant indicator for assisting in the diagnosis of various diseases, including infectious diseases, bacterial infections, HIV/AIDS, and immune deficiency disorders.

Changes in the absolute lymphocyte count help physicians assess a patient's health condition and diagnose diseases or monitor treatment effectiveness when combined with other blood test results. If the absolute lymphocyte count falls outside the normal range, timely medical consultation is recommended.