Neutrophils are a type of white blood cell that help heal damaged tissues and resolve infections. Neutrophil levels can rise or fall in response to infections, injuries, drug treatments, certain genetic conditions, and stress.
- Neutrophils are the most common type of white blood cell in the body, which makes them a first line of defense to heal injuries and fight infections.
- The amount of neutrophils in the blood typically increases if a person is sick or injured to help their body heal.
- Neutrophil levels may decrease if a person has a long-term infection, cancer, an autoimmune condition, or is taking certain medications.
Neutrophils help prevent infections by blocking, disabling, digesting, or warding off invading particles and microorganisms. They’re constantly
They also communicate with other cells to help them repair damaged cells and mount an immune response. Neutrophils play an important role in regulating the immune system and inflammation in the body.
The body produces neutrophils in the bone marrow, and they account for
When there is an infection or another source of inflammation in the body, special chemicals alert mature neutrophils, which then leave the bone marrow and travel through the bloodstream to the site in need.
Band cells are an immature form of neutrophil produced when the body is fighting an infection or inflammation. An excess of band cells in the blood is called bandemia. When this occurs, it’s typically
Unlike some other cells or blood components, neutrophils can travel through junctions in the cells that line blood vessel walls and enter into tissues directly.
In this article, we look at the reasons for high or low neutrophil levels, how doctors can test these levels, and what typical neutrophil levels are for different groups.
A note about sex and gender
Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.
There are many reasons why a person may have higher or lower levels of neutrophils in their blood.
High levels
Having a high level of neutrophils in the blood is called neutrophilic leukocytosis, also known as neutrophilia.
Rises in neutrophil levels usually occur naturally due to infections or injuries. However, neutrophil blood levels
- some medications, such as corticosteroids, beta-2-agonists, and epinephrine
- some cancers
- physical or emotional stress
- surgery or accidents
- smoking tobacco
- pregnancy
- having obesity
- genetic conditions, such as Down syndrome
- surgical removal of the spleen
Some inflammatory conditions can increase neutrophil levels, including rheumatoid arthritis, inflammatory bowel disease, hepatitis, and vasculitis.
Low levels
A low level of neutrophils in the blood is called neutropenia.
A drop in neutrophil count
An enlarged spleen may also cause a decrease in neutrophil levels. This is because the spleen traps and destroys neutrophils and other blood cells.
Some conditions and procedures that cause the body to use neutrophils too quickly include:
- severe or chronic bacterial infections
- allergic disorders
- certain drug treatments
- autoimmune disorders
Some specific conditions, procedures, and drugs that interfere with neutrophil production include:
- cancer
- viral infections, such as influenza
- bacteria infections, such as tuberculosis
- myelofibrosis, a disorder that involves bone marrow scarring
- vitamin B12 deficiency
- radiation therapy involving bone marrow
- phenytoin and sulfa drugs
- chemotherapy medications
- toxins, such as benzenes
- aplastic anemia, which is when the bone marrow stops producing enough blood cells
- severe congenital neutropenia, a group of disorders where neutrophils cannot mature
- cyclic neutropenia, which causes cell levels to rise and fall
- chronic benign neutropenia, which causes low cell levels for no apparent reason
Doctors
A doctor may order a CBC test when someone is experiencing a range of symptoms related to infection, chronic illness, or injuries, such as fever, pain, and exhaustion. A nurse or technician will draw a small amount of blood from the arm and send it away for evaluation.
If the initial results are confirmed, a doctor will perform a physical exam, ask questions about the person’s lifestyle, and review their medical history.
If there is no apparent reason for changes in white blood cell levels, the doctor will order more specific tests.
These can include:
- urine sample analysis
- blood cultures
- a chest X-ray
- CT scans
After a blood test, experts will examine the sample to see if there are any specific white blood cells,
If myeloblasts or other white blood cells appear in significant levels in the blood, the doctor will request a bone marrow sample.
Bone marrow collection involves inserting a long needle into part of the pelvis near the back of the hip. The procedure
Changes in neutrophil levels are often a sign of more significant changes in white blood cell levels.
The amount and proportion of white blood cells in the bloodstream change over time with age and other events, such as pregnancy. While everyone’s typical range is slightly different, some commonly used ranges include:
| Newborn | 13,000–38,000 per mm³ |
| Infant 2 weeks of age | 5,000–20,000 per mm³ |
| Adult | 4,500–11,000 per mm³ |
| Pregnant female (third trimester) | 5,800–13,200 per mm³ |
In adults who are not pregnant, a white blood cell blood count over 11,000 per mm³ is considered high. Neutrophilic leukocytosis occurs when a person has over 7,000 per mm³ mature neutrophils in their bloodstream.
The lower blood level limit for neutrophils in human blood is 1,500 per mm³. When a person’s levels of neutrophils are low, it is known as neutropenia. The lower the level of neutrophils circulating in the blood, the more severe neutropenia. Neutropenia levels are:
| Mild neutropenia | 1,000–1,500 per mm³ |
| Moderate neutropenia | 500–999 per mm³ |
| Severe neutropenia | below 500 per mm³ |
Minor changes in neutrophil or white blood cell levels are typically nothing to worry about as long as they are temporary. A raised white blood cell count often means the body is responding to infection, injury, or stress.
Some people have naturally lower levels of white blood cells and neutrophils than other people. This can be due to a range of factors, including congenital conditions.
If neutrophil or white blood cell levels are significantly altered for no apparent reason or remain raised or lowered, a doctor will order tests to determine the cause.
Severely high or low levels of white blood cells often require emergency care and monitoring. People with severe neutropenia
People with severe neutrophilia typically have a life threatening infection or other inflammatory illness that requires treatment, such as cancer.
The best way to correct abnormal neutrophil levels is to address and treat the underlying cause.
How to lower neutrophil levels
Neutrophilia typically occurs when the body is fighting infection or inflammation from an illness or injury. Lowering neutrophil levels involves treating the underlying cause of neutrophilia.
Treatment to lower neutrophil levels will depend on the cause of neutrophilia and
- antibiotic therapy
- anti-inflammatory therapy
- hydration therapy (IV)
- chemotherapy
People with altered neutrophil levels caused by medications or procedures may need to stop or adjust treatments.
How to raise neutrophil levels
Raising neutrophil levels involves treating the underlying cause of neutropenia.
If a person has chronic conditions that disrupt their neutrophil production, they may need to take drugs that allow the body to increase neutrophil production,
People with severely low levels of neutrophils often require monitoring, antibiotic therapy, and hospitalization to reduce the risk of severe infection.
Neutropenia can sometimes be caused by a deficiency of vitamin B12, also known as cobalamin,
Learn more about foods rich in vitamin B12 and vitamin B9.
However, people with only minor or mild changes in their neutrophil blood levels often show no symptoms and do not require treatment.
When neutrophil levels are higher or lower than usual for more than a short period, a doctor will order several tests to work out the underlying cause.
The outlook of neutropenia disorders depends on the cause of neutropenia and the organs involved. Serious infections occur in a
Neutropenia due to chemotherapy or drugs may cause remission when the treatment is over.
Neutropenia, when left untreated, is associated with a high risk of death.
What does it mean if your neutrophils are high?
High neutrophil levels, known as neutrophilia, typically indicate an acute infection, inflammation, stress, or an immune response.
It can also be a sign of more serious conditions such as cancer or chronic inflammatory diseases.
What is an alarming level of neutrophils?
A concerning level of neutrophils is generally considered to be below 1,500 or above 8,000 per microliter of blood.
However, the specific threshold can vary based on individual health conditions and clinical context.
What does neutrophil count tell you?
A neutrophil count indicates the body’s response to infection, inflammation, stress, or bone marrow function.
A high neutrophil count suggests infection or inflammation, while a low count may indicate bone marrow issues, severe infection, or a response to certain medical treatments.
What does it mean if neutrophils are low?
Low neutrophils, known as neutropenia, indicate a weakened immune system, which can result from bone marrow disorders, severe infections, certain medications, or chemotherapy.
Having an appropriate number of neutrophils in the blood and bone marrow is crucial for the immune system to work correctly and help a person heal from infection or injury.
Neutrophilia, when neutrophil levels are higher than usual, is often related to:
- infection
- illness
- injury
- physical or emotional stress
- medication use
- inflammatory conditions
Neutropenia, where neutrophil levels are lower than usual, is often related to:
- severe or chronic infection
- cancer
- drug therapy
- vitamin deficiency
- genetic conditions
It is a good idea to have regular wellness checks at a doctor’s office. Anyone with concerns about their neutrophil level or any medical condition should talk with their healthcare professional.