What Are "segs" in Lab Tests?

Neutrophils are also called polymorphonuclears or PMNs. The nucleus of mature white blood cells appear segmented, while immature white blood cells are rod-shaped and known as "bands."

Neutrophils are the first white blood cells to fight off an infection and appear within minutes after a wound is detected. They are predominantly found in the pus of a wound or injury and are responsible for the yellow-whitish color. A high neutrophil count on a white blood cell differential is a sign of acute infection.