What Does a Left Shift Mean

Left shift or blood shift is an increase in the number of immature cell types among the blood cells in a sample of blood. Many (perhaps most) clinical mentions of left shift refer to the white blood cell lineage, particularly neutrophil-precursor band cells, thus signifying bandemia.

What does it mean to have a left shift?

A left shift indicates the presence of immature neutrophils in blood and usually, but not always, indicates an inflammatory leukogram (see related links for the historical origin of this term). Immature neutrophils are usually band neutrophils, but earlier forms can be seen.

What does a left shift mean on CBC?

Today, the term “shift to the left” means that the bands or stabs have increased, indicating an infection in progress. For example, a patient with acute appendicitis might have a “WBC count of 15,000 with 65% of the cells being mature neutrophils and an increase in stabs or band cells to 10%”.