What are "bands" in a blood analysis?

In a blood analysis, "bands" refer to immature neutrophils, which are a type of white blood cell. The presence of bands is typically an indication that the body is responding to an infection, particularly bacterial infections. During such instances, the bone marrow releases these immature cells into circulation as a part of the immune response. They are an early form of neutrophils and their increased levels can be termed as a "left shift," signifying a heightened response to infection or inflammation. Monitoring the band count in blood tests helps healthcare professionals assess the severity of an infection or the body’s response to it.

Mature white blood cells are not referred to as bands and would represent a different category of white blood cells altogether. Elevated hemoglobin levels are indicators of conditions such as polycythemia, but do not relate to the presence of bands. Similarly, red blood cells are a separate component of the blood that do not include immature white blood cells and serve their own unique function in oxygen transport.