Neutrophilia (or neutrophil leukocytosis) is a condition where a person has a high number of neutrophil granulocytes in their blood.
Neutrophils are the primary white blood cells that respond to a bacterial infection, so the most common cause of marked neutrophilia is a bacterial infection.
Neutrophils are also increased in any acute inflammation , so will be raised after a heart attack or other infarct.
As well as increasing in number, neutrophils also show other changes in infection and inflammation. The neutrophils tend to be younger, as they are being released more quickly, this is called a left shift. The NAP score, (the amount of neutrophil alkaline phosphatase per neutrophil) will increase. In a severe infection, toxic granulation changes happen to the neutrophils.
Drugs, such as prednisone, have the same effect as cortisol, causing marginated neutrophils to enter the blood stream. Nervousness will very slightly raise the neutrophil count because of this effect.
A neutrophilia might also be the result of a malignancy. CML (or chronic myeloid leukaemia) is a disease where the blood cells proliferate out of control. These cells may be neutrophils.
See also