Why Are My Monocytes High?

Medically Reviewed By Julie Scott, DNP, ANP-BC, AOCNP
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Monocytes are a type of white blood cell that help your body fight off bacterial, viral, and other infections. They are a key part of a vital system responsible for your immune response. Monocytes in your bone marrow enter the bloodstream to fight infection and cancer cells and mediate cell repair. After a few hours, they move from your bloodstream into your tissue, becoming macrophages.

When you have high monocytes, known as monocytosis, you might also have an infection or are in recovery from an infection. High monocytes could also be an indicator of some forms of cancer, in particular leukemia.

This article will explain why your monocytes are high and what it means. It will also explain how monocytes keep you healthy, what a monocyte count is, and what it means.

What is a monocytes high?

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Having high monocytes, or monocytosis, means you have a larger amount of monocytes in your bloodstream.

You have five types of white blood cells that work in balance with each other. When one is high, another might be low.

As a result, when evaluating your blood count, a different type will be listed on your report. This is a leukocyte report or white blood cell count.

There are three main types of white blood cells: granulocytes, lymphocytes, and monocytes.

  • Granulocytes: Granulocytes are immune cells with small particles. Enzymes are released from these cells when the body has an infection or allergic reaction.
  • Lymphocytes: These produce antibodies to help dispose of bad bacteria and viruses.
  • Monocytes: These cells alert other blood cells to intruders and kill invaders to prevent infection.

Typically, monocytes compose a smaller percentage of your total white blood cell count. The amount of these cells in your bloodstream help determine changes in your health.

What count is a high monocyte count?  

When evaluating your monocyte count, a healthcare professional will look at the number of white blood cells in your bloodstream.

The blood cell range of each type is typically around the following:

  • Monocytes: 2–8%
  • Basophils: 0.5–1%
  • Eosinophil: 1–4%
  • Lymphocytes: 20–40%
  • Neutrophils: 55–70%

A monocyte count above 10% is considered high and a cause for concern.

When your monocyte count passes this threshold, you have monocytosis. This could result from your immune system fighting something in your body.

Read more about monocytosis here.

What are the symptoms of a monocytes high?

If you have a high monocyte count, you usually will not experience any symptoms. However, you will more likely experience symptoms of the underlying cause of your high monocyte count.

Symptoms could include:

What causes a monocytes high?

Associated with infection, a monocyte count is indicative of your body’s immune system fighting.

Your monocyte count will increase because of:

  • acute stress
  • a blood disorder
  • immune system activation
  • an infection
  • high inflammation
  • endocarditis, an infection in your heart valve
  • collagen vascular disorders, which cause inflammation in your collagen and joints
  • lung infections
  • certain medications

A doctor can determine what may be going on by looking at your full white blood cell report. Interactions between the different percentages of your white blood cell types can help them identify a specific cause.

For example, a doctor could look at monocyte and lymphocyte percentages to determine the activity of the disease in people with ulcerative colitis.  

What are the risk factors for a monocytes high?

Many conditions can raise your risk of monocytosis, including:

A high monocyte count is the most common diagnostic indication of myelomonocytic leukemia. This form of cancer begins in the cells that produce blood in your bone marrow.

Visit our leukemia hub to learn more.

How is a monocytes high diagnosed?

To determine a monocyte high, you will need a blood differential test. This test can determine the percentage concentration of each type of white blood cell, which helps your doctor detect what may be the problem.

The test could also determine how mature these blood cells are or whether they are atypical.

After a doctor draws your blood, they dye it. This helps pathologists count the types of blood cells in your sample.

How do you treat a monocytes high?

The treatment for your monocytosis will vary depending on the cause. After the blood differential test, your doctor will likely order further tests to reach a specific diagnosis, which will help them create a treatment plan.

General treatment may include antibiotics for a bacterial infection or symptom management for a viral infection.

Treatment for cancers can often include:

What are ways to keep your monocyte count down?

It is important to maintain a healthy level of monocytes. Having too few monocytes could increase your chances of disease. Your body may be responding to another issue if they are too high.

Exercising regularly is crucial for many reasons, but it is also important for maintaining the proper blood cell balance. Exercise can improve the function of monocytes, particularly as you age.

Eating a low inflammation diet can also help. This may include food items such as:

  • olive oil
  • leafy green vegetables
  • nuts
  • oil-rich fish, such as sardines and mackerel

Some foods can increase your inflammation levels, such as:

  • red and processed meats
  • fried food
  • refined carbohydrates, such as white bread and pasta
  • sugary drinks
  • butter and margarine


Due to the vital role monocytes play in the functioning of your immune system, they can be powerful indicators of your health status.

If your count is higher than it should be, your doctor can work with you to find the cause and create a treatment plan.

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Medical Reviewer: Julie Scott, DNP, ANP-BC, AOCNP
Last Review Date: 2022 Aug 8
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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