What to Know About Granulocytosis (2023)

Granulocytes are a type of white blood cell that appears granular when viewed under a microscope. Most healthy people don't have immature granulocytes in their blood at all. These cells develop in the bone marrow, where immature granulocytes (IG) will give rise to neutrophils, eosinophils, and basophils once they mature.

When IG levels are low, there's less cause for concern, although low levels of mature granulocytes may suggest a health issue that may be serious. High IG counts suggest an infection or may point to a bone marrow condition.

This article will help you to understand IGs and what low or high levels can mean. It explains the conditions associated when immature granulocytes are low or high, and how they are diagnosed and treated.

What to Know About Granulocytosis (1)

Types of Granulocytes

Granulocytes are produced in the bone marrow and they all come from the same precursor. They differentiate as they mature and prepare to fight disease. The specific roles of these mature cells include:

  • Neutrophils:The most common type of white blood cell, neutrophils help with tissue healing and fighting infections, especially bacterial infections.
  • Eosinophils: Eosinophils are associated with allergies, parasitic infections, and cancer.
  • Basophils:Basophils are granulocytes that are involved with inflammation. They can release histamine, which causes a variety of responses, and heparin, which prevents blood from clotting.

Mast cells also arise from immature granulocytes. They recognize harmful infectious organisms and aid in releasing inflammatory chemicals to help boost the immune response.

Types and Function of White Blood Cells (WBCs)

Immature Granulocytes

Immature granulocyte (IG) cells arise in the bone marrow. These cells undergo stages of development (as ametamyelocytes, myelocytes and promyelocytes) before becoming mature.

Neutrophils are the most common granulocyte in your bloodstream, accounting for up to 60% of the white blood cells. When viewed under a microscope, they develop band-like features as they mature. These are sometimes referred to as band cells.

The mature neutrophils have a short lifespan but your body produces about 100 billion of them each day.Normal neutrophil levels are between 2,500 and 6,000 neutrophils per microliter of blood. It's when your body produces too many or too few that health conditions may be at work.

Esosinophils follow a similar pathway and survive for three to five days. Basophils, making up just 1% of your white blood cells, have a normal count of between 15 and 50 per cubic millimeters (mm3).

It can sometimes be normal for pregnant people and children to have immature granulocytes (IGs) in their bloodstream. For others, the presence of IGs may indicate a health condition, some of them potentially serious.

Low IG Levels

Since immature granulocytes aren't usually in the bloodstream for healthy people, healthcare providers will likely find low levels of mature granulocytes to be of greater concern.


Low levels of mature granulocytes usually occur with an acquired condition, although there can be an underlying genetic condition in rare cases. These causes may include:

  • Autoimmune diseaseslikelupus
  • Bone marrow diseases
  • Chemotherapydrugs that kill cancer cells, or a cancer itself
  • Infections liketuberculosis(infectious disease affecting the lungs)
  • Vitamin deficiencies
  • Certain medications

Toxic exposures, such as those to lead or mercury, also can lead to low levels.


The symptoms of low granulocyte levels may be similar to those of an infection. You may experience:

(Video) White Blood Cells -- Granulocytes & Lymphocytes - Part 1

  • Fever and chills
  • Digestive tract pain (abdomen and rectum)
  • Mouth infections
  • Trouble breathing

You also may experience fatigue or dizziness, an increased heart rate, or a sudden drop in blood pressure.


While the treatment for low granulocyte levels may vary depending on your situation (for example, if the condition is chemotherapy-related) there are some main strategies for healthcare providers. They include:

  • Drugs to boost production of granulocytes in the bone marrow, such as Neupogen(filgrastim)
  • Antibiotics to prevent or treat infection
  • Bone marrow transplant to assist the production of granulocytes with healthy donor tissue

Treatment also may include lifestyle changes to help you avoid infection, like wearing a face mask in public or avoiding crowds.

High IG Levels

Mature granulocyte levels often increase with illness or infection, but the presence of immature granulocytes (IGs) in your blood samples will raise suspicion of an underlying health problem, too.

Healthcare providers may be concerned when the level of immature granulocytes reaches or exceeds a normal level of 1% of your total white blood cell count. At 2%, the level is considered high.


Causes of high IG levels, as well as high levels of mature granulocytes, often include infection and allergic reaction, but they also point to bone marrow disorders, blood-related cancer, and more. These causes of increased granulocytes include:

  • Inflammatory diseases such as vasculitis, affecting the blood vessels
  • Viral or bacterial infections, such as tuberculosis
  • Sepsis, a severe reaction to a blood infection)
  • Autoimmune diseases, such as rheumatoid arthritis
  • Bone marrow disorders
  • Cancer

The presence of elevated IG levels is a useful finding to help your healthcare provider with making a diagnosis.

Granulocytes and Lifestyle

Granulocytes also increase in response to certain lifestyle conditions, including chronic sleep disruption and smoking.This low-grade granulocytosis is not the same as an infection or medical illness, but is believed to contribute to health complications.


Some medical conditions can cause granulocytes to increase. This can cause symptoms such as:

  • Swelling
  • Pain
  • Fatigue
  • Fever

However, certain medical issues can cause specific symptoms. Examples include:

  • Tuberculosis, with a cough, hemoptysis (coughing blood), chest pain, and a fever
  • Vasculitis and fever, as well as an area of swelling, redness, and tenderness. This may develop on the leg or other areas of the body.
  • Medication use that leads to bleeding, increased risk of infections, and symptoms of anemia


Treatment for high levels of granulocytes can include antibiotics to prevent or treat infection. It also may include allergy medication. When these high levels help to reveal a cancer diagnosis, treatments may include chemotherapy, radiation, and other cancer care.

Chronic Myeloid Leukemia

Chronic myeloid leukemia (CML) is a type of blood cancer that occurs when the bone marrow makes too many white blood cells. Depending on the phase of CML, immature granulocytes may be seen in your blood and bone marrow.The finding may be the first sign of the condition when there aren't yet other symptoms.


Granulocytosis is diagnosed with a blood test called a complete blood count (CBC). This test measures different types of blood cells, including white blood cells, red blood cells, platelets, and some other characteristics of blood, such as hemoglobin and hematocrit (the ratio of red blood cells to other blood elements by volume).

Granulocytes are measured as the number of cells per cubic millimeter and as a percentage of total leukocytes (white blood cells). Lymphocytes are a type of leukocyte, and granulocytes are a type of leukocyte. Standard values may vary from one lab to another, but the values below are widely accepted.

Normal granulocyte values
Cells per cubic millimeterPercent of total leukocytes
Total lymphocyte count1,000–4,00020%–40%
Mast cellsnot measured by standard tests

If you have granulocytosis, you may need further testing with a blood smear, imaging tests, or a biopsy (removing a sample of tissue for analysis in a lab), such as a bone marrow biopsy, to identify the cause.

With some conditions, including cancer and bone marrow disease, granulocytes can increase at times and decrease at other times. In fact, the change in number can signal different disease stages.

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For example, granulocytes can be elevated during flare-ups of inflammatory disease. And some cancers may cause granulocytosis in early stages, with decreased granulocytes in later stages or as a result of treatment that affects the bone marrow.


Granulocytosis is an increase in granulocytes in the blood. Granulocytes are a type of white blood cell that helps the body fight infections. Granulocytosis can be an increase in mature or immature granulocytes, and it can occur due to infections, inflammation, or cancer.

Sometimes granulocytosis resolves if the condition is temporary, like an infection. At times, granulocytosis is a sign of a serious medical illness and further tests, such as a biopsy, may be needed.

If you need treatment, you will likely have repeat blood tests to see if your granulocytosis is resolving. Follow-up blood tests can help monitor treatment and follow the progression of your underlying condition.

Frequently Asked Questions

  • Is granulocytosis treatable?

    Yes, often granulocytosis can be treated. Generally, specific therapies that treat the cause are used. For example, chronic myeloid leukemia is treated with chemotherapy, and inflammatory disorders may be treated with interventions that suppress excessive immune system activity.

  • What is an immature granulocyte?

    An immature granulocyte is not fully developed into the mature version of a specific (differentiated) cell type. IGs are normally found in the bone marrow, and some medical conditions can cause them to enter the blood.

  • Can somebody have a low granulocyte count?

    Yes, one or more types of granulocytes can be low. This is a sign of health problems, such as bone marrow disorders, and it can also occur as a side effect of medications and treatments that interfere with the production of blood cells in the bone marrow.

14 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Georgakopoulou VE, Makrodimitri S, Triantafyllou M, Samara S, Voutsinas PM, Anastasopoulou A, et al. Immature granulocytes: Innovative biomarker for SARS‑CoV‑2 infection. Mol Med Rep. 2022 Jul;26(1):217. doi:10.3892/mmr.2022.12733.

  2. McCracken JM, Allen LA.Regulation of human neutrophil apoptosis and lifespan in health and disease.J Cell Death. 2014 May 8;7:15-23. doi:10.4137/JCD.S11038.

  3. American Cancer Society.Understanding your lab test results.

  4. American Cancer Society. Low White Blood Cell Counts.

  5. Abdel-Azim H, Sun W, Wu L.Strategies to generate functionally normal neutrophils to reduce infection and infection-related mortality in cancer chemotherapy.Pharmacology & Therapeutics. 2019;204:107403. doi:10.1016/j.pharmthera.2019.107403

  6. SelfDecode Labs. Granulocytes: Immature, High, Low & Normal Levels.

  7. Endo A, Komagata Y, Yamagishi K, Kawashima S, Arimura Y, Kaname S. Two distinct subsets of LDGs (low density granulocytes) in ANCA-associated vasculitis. Mod Rheumatol. 2021:1918883. doi:10.1080/14397595.2021.1918883

  8. Osei-Boakye F, Addai-Mensah O, Owusu M, Saasi AR, Appiah SK, Nkansah C, Wiafe YA, Debrah AY. Effect of pulmonary tuberculosis on natural anticoagulant activity in therapy-naïve Ghanaian adults; a case-control study. J Immunoassay Immunochem. 2022:1-17. doi:10.1080/15321819.2021.2001002

  9. Jeon K, Lee N, Jeong S, Park MJ, Song W. Immature granulocyte percentage for prediction of sepsis in severe burn patients: a machine leaning-based approach. BMC Infect Dis. 2021;21(1):1258. doi:10.1186/s12879-021-06971-2

  10. Snoderly HT, Nurkiewicz TR, Bowdridge EC, Bennewitz MF. E-Cigarette use: device market, study design, and emerging evidence of biological consequences. Int J Mol Sci. 2021;22(22):12452. doi:10.3390/ijms222212452

  11. Streng AA, Loef B, Dollé MET, van der Horst GTJ, Chaves I, Proper KI, van Kerkhof LWM. Night shift work characteristics are associated with several elevated metabolic risk factors and immune cell counts in a cross-sectional study. Sci Rep. 2022;12(1):2022. doi:10.1038/s41598-022-06122-w

  12. American Society of Clinical Oncology. Leukemia - chronic myeloid - CML: phases.

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  13. National Institute of Health. Normal blood values.

  14. Hou YC, Lin JL, Huang WH, et al. Outcomes of patients with acetaminophen-associated toxic hepatitis at a far east poison center. Springerplus. 2013;2:674. doi:10.1186/2193-1801-2-674

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What to Know About Granulocytosis (2)

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When should I be concerned about high granulocytes? ›

Healthcare providers may be concerned when the level of immature granulocytes reaches or exceeds a normal level of 1% of your total white blood cell count. 6 At 2%, the level is considered high.

What are some facts about granulocytes? ›

Granulocytes are a type of white blood cell that has small granules inside them. These granules contain proteins. The specific types of granulocytes are neutrophils, eosinophils, and basophils. Granulocytes, specifically neutrophils, help the body fight bacterial infections.

What happens if granulocytes are high? ›

A high granulocyte count (granulocytosis) could indicate a number of issues, including infection, blood cell cancer or some type of autoimmune disease. Bone marrow conditions are also a primary cause of granulocytosis. (Bone marrow is the spongy tissue inside of your bones.

How high is too high for granulocytes? ›

More than 2% immature granulocytes is a high count.

What kind of infection causes high granulocytes? ›

High granulocytes can happen if the immune system is fighting off an infection that is:
  • Viral.
  • Bacterial.
  • Fungal.
  • Parasitic.
Jun 16, 2023

How is high granulocytes treated? ›

For this reason, granulocytosis treatment depends on the associated health problem. For example, if you have granulocytosis that's caused by cancer, your treatment may include chemotherapy, radiation therapy or a bone marrow transplant. For other conditions, treatment may involve medications or blood transfusions.

What infections do granulocytes fight? ›

Granulocytes, specifically neutrophils, help the body fight bacterial infections. The number of granulocytes in the body usually increases when there is a serious infection. People with a lower number of granulocytes are more likely to develop serious infections.

What is the life expectancy of granulocytes? ›

The lifespan of the neutrophilic granulocyte is at least 2 days. This is much longer that what has been described in the scientific literature (usually approx. 1 day). This is the result of innovative studies on human granulocyte kinetics with deuterium-labelled cells, performed in the PhD-project of Marwan Hassani.

What do granulocytes have in common? ›

Granulocytes are white blood cells that help the immune system fight off infection. They have a characteristic morphology; having large cytoplasmic granules, that can be stained by basic dyes, and a bi-lobed nucleus.

What triggers granulocytes? ›

High granulocytes can have various underlying causes, including infections, inflammation, tissue damage, bone marrow disorders, medication, cancer, pregnancy, and many others. Work with your doctor to get an accurate diagnosis.

Can stress cause high granulocytes? ›

Our data suggested that granulocytes were more active in the response induced by acute stress. Correspondingly, acute stress led to a significant decrease of T cells and B cells and a significant increase of neutrophils in peripheral blood, which supported our hypothesis.

What is a normal granulocyte percentage? ›

About two thirds of the body's white blood cells should be granulocytes. Low granulocytes, a condition called granulocytopenia, makes the body more prone to infections. Of the body's white blood cells, an average count of neutrophils is 50-70% (2500-7000 absolute count).

What does Gran mean in a blood test? ›

Gran is short for granulocyte. The White Blood Count (WBC) in a blood test result is broken down into Granulocytes (GRAN) and Lymphocytes (LYM). White blood cells are part of the immune system. An elevated level of granulocytes is indicative of a bacterial infection. Viral infections can cause low lymphocyte counts.

Why do I always have high white blood cells? ›

Causes of an elevated white blood cell count include infection, abnormalities in the bone marrow, smoking, chronic lung disease, immune disorders, inflammatory or allergic reactions or even physical and emotional stress.

Can inflammation cause high immature granulocytes? ›

Background: Immature granulocytes (IG) level in peripheral blood is used as early sign of infection. On the other hand, IG could be elevated in other conditions like inflammatory or cancerous diseases and in pregnancy.

What is the earliest stage of granulocytes? ›

The first recognizable granulocytic precursor is the myeloblast. Early granulocyte precursors (myeloblast and promyelocyte) appear similar between the various granulocytic cell lines until the myelocyte stage, which is the final stage capable of cell division.


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