High Levels of Monocytes in the Blood: Symptoms and Treatments

Although infections are the most common cause of high levels of monocytes in the blood, this can also occur due to a carcinogenic or inflammatory process.
High Levels of Monocytes in the Blood: Symptoms and Treatments

Written by Carmen Martín

Last update: 27 May, 2022

Our blood contains many more cell types and substances than most people typically know. A good example of this is monocytes. Monocytes are immune system cells that circulate in the blood.

The bone marrow produces monocytes, which then reach various tissues through the blood. When they reach the tissues, they become macrophages and perform their defense function. They’re responsible for removing certain waste products and dangerous elements from the body. Moreover, these cells also act in inflammatory processes.

Overall, monocytes represent between 4 and 8% of the total cells in the blood. However, their concentration varies depending on age, infections, or if there’s an active inflammatory process.

In this article, we’ll explain why you may have high levels of monocytes in your blood. This is an essential factor to be taken into account during a blood test or when it comes to knowing a person’s immune status.

Why do blood monocyte levels elevate?

As we mentioned above, monocytes are cells that belong to the immune system. They’re key players in inflammatory and infectious processes. Medical professionals consider their levels high when their amount exceeds 8% of all blood cells.

High levels of monocytes in the blood don’t have to cause symptoms. However, what usually do manifest are the symptoms and signs of the situation that’s causing this increase. In short, we can say that the most common causes are:

  • Infections. The truth is that infections are the most common cause, even if they’re transient infections.
  • Autoimmune and inflammatory diseases. The most common of these is rheumatoid arthritis.
  • Blood disorders.
  • Carcinogenic processes, such as leukemia and lymphoma.
A doctor holding a blood test.
Blood tests allow medical professionals to know the number of white blood cells and red blood cells present in the body.

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High levels of monocytes due to infection

This is the most common cause. Monocyte levels elevate both due to a simple infection, such as a cold, as well as a chronic infection, like tuberculosis. However, blood tests that show high levels of monocytes are non-specific.

Inflammatory diseases

These cells may also be an indication that there’s an inflammatory process in the body. This is the case of rheumatoid arthritis. It’s a chronic inflammatory disorder that affects the joints and causes pain and loss of mobility.

Blood neoplasms

The blood cells may also experience neoplastic processes. This means that different types of cells can grow uncontrollably and increase their concentration. Thus, this may also be a cause of high levels of monocytes in the blood.

Red and white blood cells.

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How doctors detect high levels of monocytes in the blood

Blood tests that include a complete blood count show all the cells present in the blood. This is a simple and effective method to detect this situation. However, as we indicated above, some data are nonspecific and should be studied more deeply.

Depending on the number of monocytes, it’s more likely that it’s due to a process or another. For example, if the levels are slightly elevated, it’s probably due to a mild infection. On the other hand, if the levels are excessively high, they may be indicative of leukemia.

The doctor will be responsible for analyzing the concentration of monocytes. As they deem necessary, they may request other tests to find the infection or inflammatory process, if they exist. Therefore, it’s very important to know if the patient has other symptoms that accompany this fact. There’s no treatment for high blood monocytes. Instead, the treatment is focused on solving the underlying cause.

Nevertheless, we should also emphasize that exercise can be a way to improve your monocyte count. This is because exercise helps regulate immune system functioning and acts as a natural anti-inflammatory.

In conclusion, it’s important to remember that high levels of monocytes is a very nonspecific sign. You need to see your doctor to get diagnosed. In addition, most of the time, it’s a consequence of a mild passing infection.


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This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.