Neutrophils
Also known as: Neutrophil Count, Neut
What Does Neutrophils Measure?
Neutrophils are a type of white blood cell and the most abundant immune cell in the human body, typically making up 50-70% of all white blood cells. A neutrophil count measures either the absolute number of neutrophils per microliter of blood (Absolute Neutrophil Count, or ANC) or their percentage of total white blood cells. These cells are produced in the bone marrow and are the immune system's first responders, rapidly migrating to sites of infection or tissue damage.
Why Does Neutrophils Matter?
Neutrophils are the frontline defenders against bacterial and fungal infections, engulfing and destroying pathogens through a process called phagocytosis. Monitoring neutrophil levels is critical for assessing immune function, diagnosing infections, identifying blood disorders, and evaluating bone marrow health. Abnormal neutrophil counts can signal serious conditions ranging from acute infections and inflammatory diseases to leukemia and bone marrow failure. They are especially important for monitoring patients undergoing chemotherapy, as low neutrophil counts dramatically increase the risk of life-threatening infections.
Normal Ranges
Males
1,800–7,700 cells/µL (absolute); 50–70% of total WBC
Females
1,800–7,700 cells/µL (absolute); 50–70% of total WBC
Children
Varies by age; newborns 6,000–26,000 cells/µL, children 1,500–8,500 cells/µL
Causes of High Levels
- Bacterial or fungal infections triggering an acute immune response
- Physical or emotional stress causing release of stored neutrophils
- Corticosteroid medications (e.g., prednisone) mobilizing neutrophils from bone marrow
- Chronic inflammatory conditions such as rheumatoid arthritis or inflammatory bowel disease
- Certain cancers, particularly chronic myeloid leukemia (CML) or other myeloproliferative disorders
- Smoking, which chronically elevates circulating neutrophil levels
Causes of Low Levels
- Viral infections (e.g., influenza, HIV, hepatitis) suppressing bone marrow production
- Chemotherapy or radiation therapy destroying rapidly dividing bone marrow cells
- Autoimmune conditions such as lupus attacking neutrophils or bone marrow
How to Improve Your Neutrophils
Diet
- Eat folate-rich foods such as leafy greens, lentils, and chickpeas to support bone marrow cell production
- Include vitamin B12 sources like eggs, dairy, meat, and fortified cereals to prevent deficiency-related neutropenia
- Consume copper-containing foods such as shellfish, nuts, seeds, and whole grains to support neutrophil maturation
- Add zinc-rich foods like pumpkin seeds, beef, and legumes to enhance immune cell development
- Limit excessive alcohol, which impairs bone marrow function and reduces neutrophil production
Supplements
- Vitamin B12 (500–1,000 mcg/day) if deficient, to support bone marrow health and neutrophil production
- Folate/Folic Acid (400–800 mcg/day) for individuals with low levels affecting blood cell production
- Copper (1–2 mg/day) if deficient, to support neutrophil maturation and function
- Vitamin C (500–1,000 mg/day) to support neutrophil function and antioxidant protection
- Zinc (8–11 mg/day from diet or supplement) to support immune cell development and neutrophil activity
Related Biomarkers
Frequently Asked Questions
What does it mean if my neutrophils are high?
A high neutrophil count, called neutrophilia, most commonly indicates that your body is fighting a bacterial infection. It can also occur in response to physical stress, corticosteroid medications, inflammation, or in some blood cancers. A single elevated reading is often not cause for alarm, but your doctor will evaluate it alongside your symptoms and other lab results to determine the cause.
What does it mean if my neutrophils are low?
A low neutrophil count, called neutropenia, means your immune system may have difficulty fighting bacterial and fungal infections. It is commonly caused by viral infections, chemotherapy, certain medications, autoimmune diseases, or nutritional deficiencies. Severe neutropenia (ANC below 500 cells/µL) significantly increases infection risk and often requires medical monitoring or treatment.
What is a dangerously low neutrophil count?
An Absolute Neutrophil Count (ANC) below 1,500 cells/µL is considered neutropenia. Levels below 1,000 cells/µL carry a moderate infection risk, while levels below 500 cells/µL are considered severe neutropenia and represent a medical emergency requiring immediate evaluation. Patients at this level are highly vulnerable to life-threatening bacterial and fungal infections.
Can neutrophil levels change day to day?
Yes, neutrophil counts can fluctuate significantly from day to day based on factors such as stress, physical activity, time of day, recent illness, medications, and even hydration status. A single abnormal reading should always be interpreted in context. Doctors typically look at trends over time or combine the count with clinical symptoms and other tests before making a diagnosis.