Granulocytosis occurs when there are too many granulocytes (a type of white blood cell) in your blood. It’s a symptom of many different conditions, including infections, autoimmune diseases and blood cell cancers. As a result, people with granulocytosis can develop varying symptoms and warning signs. Treatment targets the underlying condition.


What is granulocytosis?

Granulocytosis occurs when there are too many granulocytes in your blood. The term “granulocytes” refers to a category of white blood cells that includes neutrophils, eosinophils and basophils — which all work together to fight off inflammation, infections and allergens inside of your body.

Granulocytes get their name from the granules found inside them. (Granules are particles in a cell’s cytoplasm that are visible when viewed under a microscope.)


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What does it mean when your granulocytes are high?

If your granulocyte count is high, it usually indicates infection. Other conditions closely associated with granulocytosis include autoimmune diseases (such as rheumatoid arthritis) and bone marrow conditions (such as chronic myeloid leukemia [CML]).

Agranulocytosis and granulocytosis: What’s the difference?

Granulocytosis is characterized by too many granulocytes in your blood. In contrast, agranulocytosis is a condition in which your bone marrow doesn’t make enough granulocytes.

Leukocytosis vs. granulocytosis

Sometimes, the terms “leukocytosis” and “granulocytosis” are used interchangeably, but there are minor differences between the two. While granulocytosis technically refers to an increase in the number of granulocytes (neutrophils, eosinophils and basophils), leukocytosis refers to an increase in the number of all white blood cells (granulocytes, monocytes and lymphocytes).


Symptoms and Causes

What are the symptoms of granulocytosis?

Granulocytosis symptoms vary significantly and depend on the underlying cause. For example, people who have granulocytosis as the result of rheumatoid arthritis may have joint pain, stiffness and swelling. Those who have chronic myeloid leukemia-related granulocytosis often experience fatigue, night sweats, abnormal bleeding and pale skin. When granulocytosis is the result of a bacterial infection, common symptoms include headache, fever, fatigue, nausea and vomiting.

What causes granulocytosis?

It’s important to note that granulocytes are a normal part of your immune system. They help protect your body from harmful viruses and bacteria. But when there are too many granulocytes in your blood, it usually means you have some type of health problem. Granulocytosis can develop in combination with infections, autoimmune disorders and bone marrow disorders, such as chronic myeloid leukemia (CML), primary thrombocythemia and polycythemia vera.

Other granulocytosis causes may include:


Diagnosis and Tests

How is granulocytosis diagnosed?

Your healthcare provider will perform a physical examination. If they suspect granulocytosis, they’ll order a complete blood count (CBC). This test requires a small sample of your blood, which will be sent to a pathology lab for analysis.

Normal range vs. granulocytosis range

The normal range for each type of granulocytes is:

  • Neutrophils: 1,800 – 7,800 cells per microliter of blood.
  • Eosinophils: 0 – 450 cells per microliter of blood.
  • Basophils: 0-200 cells per microliter of blood.

Anything above these levels indicates granulocytosis. Lab test results can be confusing and difficult to interpret. To learn more, talk with your healthcare provider.

Management and Treatment

How is granulocytosis treated?

Granulocytosis isn’t really a separate disease. Instead, it’s a symptom of many other conditions. 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.

No matter what your underlying condition, your healthcare provider can determine the most appropriate course of treatment. Addressing the underlying condition should also reduce the number of granulocytes found in your blood.


Can I prevent granulocytosis?

Because granulocytosis is associated with many unavoidable diseases and conditions, there’s no known way to prevent it altogether. If you develop granulocytosis, your healthcare provider will determine the cause and recommend the best treatment for your needs.

Outlook / Prognosis

What can I expect if I have granulocytosis?

If a complete blood test (CBC) indicates that you have granulocytosis, then your healthcare provider will begin looking for conditions that may have caused it.

How long does granulocytosis last?

Typically, granulocytosis goes away once the underlying health condition is treated. This could take a few days to several weeks, depending on your situation.

Living With

When should I see my healthcare provider?

You should visit your healthcare provider any time something doesn’t feel quite right. Many granulocytosis symptoms overlap with other conditions, so it’s important to schedule an examination so your healthcare provider can figure out what’s causing your issues.

If you’re already undergoing treatment for a granulocytosis-related condition, call your healthcare provider any time you notice changes. They’ll help find ways to manage your symptoms.

What questions should I ask my healthcare provider?

Understanding your test results can help you make informed decisions about your health. If you have granulocytosis, here are some questions you may want to ask your healthcare provider:

  • How high is my granulocyte count?
  • What conditions are you testing for?
  • What kinds of tests or assessments are necessary?

A note from Cleveland Clinic

Granulocytes are an essential part of your immune system. These cells help defend your body against a variety of infections. But if you have too many granulocytes in your blood, it could indicate a more serious health issue. If you have granulocytosis, your healthcare provider will start looking for the root cause of your problem. Once that’s determined, they’ll design a personalized treatment plan. If cancer is part of your diagnosis, talk to your healthcare provider about the many resources and support groups available to you.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 01/21/2022.

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