What Is Neutrophilia?

B. Chisholm

Neutrophils are white blood cells that play a major role in the immune system. Neutrophilia refers to a higher than normal number of neutrophils, which may be caused by infection, inflammation or chronic disorders such as chronic myeloid leukemia. The neutrophil count is a valuable tool used by doctors to diagnose a wide variety of medical conditions, in conjunction with other tests.

A neutrophil.
A neutrophil.

White blood cells, or leukocytes, are manufactured in the bone marrow and are divided into a number of subtypes, including neutrophils, which are polymorphonuclear granulocytes. This refers to their nucleus, which is multi-lobed, and the granular nature of their cytoplasm, allowing easy distinction under the microscope in the lab. Neutrophils can be divided into bands, which are newly formed neutrophils, and segmented neutrophils, which are mature.

A diagram of the effects of leukemia, one cause of neutrophilia.
A diagram of the effects of leukemia, one cause of neutrophilia.

The immune system is complicated and consists of numerous processes designed to protect the body from foreign bodies such as bacteria. Neutrophils are involved in the first response to any attack. When the body recognizes something foreign, such as bacteria, a series of signals are sent, and neutrophils gather at that point. The neutrophils then phagocytose, or envelop the foreign body, and kill it.

Acute infectious conditions such as chicken pox as well as bacterial infections and non-infectious conditions such as burns, heart attacks and chronic myeloid leukemia may cause neutrophilia. Some drugs, such as corticosteroids, may also raise neutrophils as a side effect. While some people have naturally higher neutrophil counts than others, very elevated counts should generally be investigated.

There are some non-harmful causes of slight neutrophilia, such as stress or exercise. Newborn babies tend to have higher neutrophil levels for about three days after birth. Post-operatively, a significant rise in neutrophils may be seen within three hours. Cigarette smoking has also been associated with this condition.

A leukemoid reaction, or raised white blood cell count, may be caused by drugs, infections and hemorrhage, among other causes. It results in a left shift, which means there is a higher proportion of younger neutrophils and neutrophil-precursor cells. This, simply put, shows that the body is trying to produce more white blood cells to fight off an infection or attack of some sort.

Neutrophilia is diagnosed with a blood test and microscopic examination. When checking for the condition, the doctor will normally take into account the total white blood cell count and the breakdown into the different kinds of white blood cells. This allows for more accurate diagnosis of the underlying cause of the neutrophilia.

A diagram showing different types of white blood cells, including neutrophils.
A diagram showing different types of white blood cells, including neutrophils.

You might also Like

Readers Also Love

Discussion Comments


Most of the time when a higher than normal white blood cell count is diagnosed for someone it usually isn't of major concern but it can be the first step in determining a serious problem. But, I will say that doctors are trained professionals and they understand that a high white blood cell count will usually be the result of something non-threatening and will look for other symptoms of something that may be serious.


You may want to get on top of having those tests done. I was told the same thing by my doctor during a physical and she warned me of the worst case scenarios that could occur as a result of a high white blood cell count.

Even though a high white blood cell count is usually nothing to be concerned about, it does not hurt to have a couple tests done in your lifetime to make sure that you do not have a serious problem. Although the odds of having something seriously wrong with your high white blood cell count is very minute, it is a lot better to be safe than sorry with things concerning your health.


As someone who has a high white blood cell count I found this article to be very informative. Every time I have a physical the performing doctor will always comment on my high white blood cell count and suggest about having tests done. After reading this article I may have to think about taking one of these tests.

Post your comments
Forgot password?