Normal range of neutrophil to lymphocyte ratio
Nov 24, 2022
Source: Cainiu Health
Dr. Zhang Heyang
Introduction
The neutrophil-to-lymphocyte ratio refers to the proportion of neutrophils to lymphocytes, which changes with age. At birth, neutrophils are relatively high, accounting for approximately 65%, while lymphocytes make up about 30%. After age 6, neutrophils account for 65%. After age 8, the proportions of neutrophils and lymphocytes become similar to those in normal adults, with neutrophils comprising 50–70% and lymphocytes 20–40%.
The neutrophil-to-lymphocyte ratio refers to the proportion of neutrophils to lymphocytes, which changes with age.
At birth, neutrophils are relatively high, accounting for about 65%, while lymphocytes make up approximately 30%. Around 4–6 days after birth, neutrophils and lymphocytes become roughly equal, each comprising about 50%. During early childhood, lymphocytes account for around 60% and neutrophils about 35%. By ages 4–6, lymphocytes and neutrophils each represent approximately 50%. After age 6, neutrophils gradually increase to about 65%, while lymphocytes decrease. After age 8, the proportions of neutrophils and lymphocytes approach those seen in normal adults: neutrophils constitute 50–70% of all white blood cells, and lymphocytes 20–40%.
A decreased lymphocyte percentage accompanied by an increased neutrophil percentage is usually caused by bacterial infections such as those due to Staphylococcus aureus or hemolytic streptococci. In adults, an increased lymphocyte percentage with a decreased neutrophil percentage is typically due to viral infections causing illnesses like the common cold or rubella. However, in children under 6 years old, an elevated lymphocyte percentage with reduced neutrophil percentage is considered a normal physiological phenomenon.
