High or Low Monocytes in Blood Test – What Does It Mean?

Monocytes are a type of white blood cell, and their function is to fight infections, germs, and inflammation, and to keep your immune system healthy. Doctors check blood test results for low or high monocyte levels to help diagnose various health conditions. For example, high monocyte count can mean that your body is fighting infections or that you have an inflammatory condition. Low monocyte count can mean that you have a vitamin deficiency, anemia, or are under a lot of stress.

For example, if monocytes are high because of an infection or inflammation, you might have a fever, sore joints, chronic cough, or chest pains. If monocytes are abnormally low, then you might show signs of fatigue, leg cramps, lightheadedness, or signs of acute stress.

In this article, I will look at what it means if monocytes are high or low in blood test results. Knowing the symptoms of abnormal mono levels can help to diagnose the reason for elevated or decreased white blood cell count.

What are Monocytes in Blood Test?

Complete blood count (CBC) tests check the number of white blood cells, red blood cells, and platelets to evaluate your general health. Doctors from the National Institutes of Health say that monocytes are a type of immune cell that develops in the bone marrow. Monocytes travel through the blood to tissues in the body where they can become macrophages or dendritic cells.¹

According to Dr. Mary Territo from the Division of Hematology and Oncology at UCLA, blood testing for monocyte count as part of a CBC is usually done if a person shows signs of infection or an autoimmune disorder.²

However, doctors don’t just use the number of absolute monocytes to help diagnose health conditions. They also take into consideration the differential white blood cell count. Professor of Immunology Dr. Choladda Vejabhuti Curry explains that the differential white blood cell count checks the relative percentage of all the types of white blood cells. These are lymphocytes, neutrophils, eosinophils, and basophils.³

Absolute Monocyte Count vs. Relative Monocyte Count

The monocyte count in the differential blood test is given as a percentage of the total white blood cell count – this is called relative monocyte count. For example the normal relative monocyte count is 2%-10% of the total white blood cell (WBC) count.

The absolute monocyte count is the actual number of monocytes per liter of blood. The absolute monocyte count can be found by multiplying the total WBC count by the percentage of the monocyte count.

What are Low, Normal and High Monocytes in Lab Test Results?

The average number of monocytes as part of your white blood cell count is measured in cells/liter.

According to Dr. Hina Naushad on Medscape, the normal range of monocytes is 0.2-1.0 x 10⁹/L (2%–10%).³

What if absolute monocytes are low? Low monocytes count is called monocytopenia. Anything below 2% of the total white blood cell count shows that your body isn’t producing enough monocytes or they are getting destroyed too early. This is a reading of below 0.2 x 10⁹/L.

What does it mean when monocytes are high? A high monocyte count is referred to medically as monocytosis. Different labs have different ranges on what high level of monocytes in a blood test are. This shows that your body is fighting an infection and isn’t always something to worry about. The number of monocytes in a blood test is considered high when it is over 8% to 10% of total white blood cell count, or higher than 0.8 to 1.0 x 10⁹/L.

Symptoms of Abnormal Mono Levels

Although having high or low monocyte levels show up in a blood test won’t produce any symptoms themselves, you may show signs of the cause of abnormal mono levels. Let’s look briefly at what some of these could be.

Infections

Bacterial or viral infections are one of the most common symptoms of abnormal mono levels. For example, the Journal of Dental and Medical Sciences reported that common reasons for monocytosis (high monocyte count) include:⁴

• Acute viral infections
• Tuberculosis
• Pneumonia
• Bronchial asthma
• Appendicitis

Inflamed and stiff joints

Another symptom of abnormal monocytes in lab blood test results is inflamed joints caused by arthritic conditions. According to the Journal of Leukocyte Biology, high mono levels can be a sign of chronic inflammatory diseases like rheumatoid arthritis or lupus.⁵

Easy bleeding

Chronic low mono levels may result in a person bleeding easily or having unexplained bruising. The journal Mayo Clinic Proceeding reports that monocytopenia (low monocyte count) is a feature of some types of leukemia. Because leukemia can also cause low platelet count, easy bleeding is often a sign.⁶

Losing weight without trying

Low monocytes in a blood test result may be accompanied by unexplained weight loss. This is also often a symptom of leukemia, and doctors will need to perform additional tests to find the cause of low mono count along with weight loss.

Severe mood swings

Interestingly, severe mood swings and depression could mean that blood test results show high monocyte levels. According to the Journal of Psychiatric Research, elevated white blood cell count, including monocytes, is often seen in lab test results of people who suffer from depression.⁷

Signs of liver disease

The journal Blood reported that symptoms of liver disease are sometimes associated with increased levels of monocytes. The elevated monocyte count is due to inflammation in the liver and can be used to diagnose the severity of the condition.⁸

Causes of Low Mono Levels

There are various reasons why blood test results show a low monocyte count. Let’s look in more detail at some of these reasons.

Rheumatoid arthritis

Low monocyte count can show up in blood test results if you have inflammatory diseases like rheumatoid arthritis. Depending on the type of rheumatoid arthritis you have, you may have elevated or low mono levels.

The British Journal of Rheumatology reports that monocytopenia and low white blood cell count can occur in patients with rheumatoid arthritis.⁹

If you suffer from painful inflammation in your joints, please read my article on how to manage arthritis symptoms with diet. You might also find that turmeric can help to reduce inflammation and ease your symptoms of rheumatoid arthritis.

Lupus

Lupus is another autoimmune disease that can result in below normal levels of monocytes. Lupus can cause achy joints, redness on your face, unexplained bruising, or mottled skin on your legs or hands.

According to research published in the journal Acta Haematologica, low white blood cell count including decreased levels of monocytes and lymphocytes is a common feature of lupus.¹⁰

Acute viral infections

Some acute viral infections can cause your monocyte levels to drop because the virus affects monocyte production.

The journal Clinical Infectious Diseases reported that genital papillomavirus infections, fungal infections, and certain bacterial infections can all cause a low monocyte count.¹¹

Stress

If you are under a lot of emotional or psychological stress, it could be that you see a temporary drop in mono levels. Stress can affect your body in many ways and make you feel fatigued, put up your blood pressure, cause gastrointestinal problems, and weaken your immune system. The result of this is decreased mono count in blood test results.

The International Journal of Neuroscience reported on an experiment on healthy individuals to see how the body reacts to stress. After one hour of putting the patients under stress, scientists noted that there was a drop in white blood cells, including monocytes.¹²

The results of the study may show why we are more susceptible to infections, colds, and flu when we are dealing with unresolved stress and anxiety. There are many ways to deal with anxiety and stress including using essential oils for stress, getting enough sleep, and regularly exercising.

Vitamin B12 deficiency or anemia

A vitamin B12 deficiency can cause low absolute monocyte count in a regular complete blood cell count lab test. If the low mono count is due to a vitamin B12 deficiency you will also show signs of anemia like lack of energy, brain fog, muscle weakness, or mood swings.

The journal Seminars in Hematology reported that issues with bone marrow production can cause a low red blood cell count. This can result in increased mean corpuscular red blood cell volume as well as monocytopenia. The journal said that causes of this type of anemia include viral infections, nutritional deficiencies, smoking, or overindulgence in alcohol.¹³

If doctors suspect any kind of anemia that causes decreased monocyte levels, they may check the average concentration of hemoglobin (MCHC) in your blood cells or check your average red blood cell size (RDW).

For more information on how to resolve a vitamin B12 deficiency, please read my article on how to increase levels of vitamin B12 naturally.

Tuberculosis

Tuberculosis is an infectious bacterial infection in your lungs that can cause a bad cough, pain in the chest, or coughing up blood.

Blood tests from patients with tuberculosis (TB) usually show monocytopenia and low levels of other white blood cells. This also can result in severe anemia as the bone marrow can’t produce enough red and white blood cells.¹⁴

Leukemia

Leukemia usually causes a significant drop in monocyte levels and is a serious condition that requires prompt medical treatment.

Doctors from the Mayo Clinic says that leukemia usually affects the white blood cells because leukemia causes abnormalities in the white blood cells. In time, the abnormal white blood cells overtake healthy white blood cells causing the absolute WBC to drop.¹⁵

If you have persistent signs like frequent infections, unexplained weight loss, tiny red spots under your skin, or easy bleeding, you should speak to your doctor.

Causes of High Monocyte Count

Because infections and inflammation cause your immune system to send out white blood cells to destroy germs and microbes, a high monocyte count is often more common than low monocyte levels.

Let’s look at what it means when monocytes are high.

Chronic inflammation or infections

A high monocyte count can be a marker for chronic inflammation or that your body is fighting infections.

According to the journal Medicine, some of the types of infections or inflammatory conditions that can raise your monocyte levels above normal include:¹⁶

• Bacterial infections
• Fungal infections
• Parasite infections
• Coronary heart disease and inflammation of the lining of the heart
• Rheumatic disorders
• Lung disease and infections

Tuberculosis

As well as causing low monocytes count, tuberculosis can also cause a spike in monocyte levels.

The Journal of Tropical Pediatrics reported that tuberculosis in children commonly causes signs of anemia with higher than normal levels of monocytes. It was also noted that other respiratory infections can also cause similar symptoms.¹⁷

Cardiovascular disease

Inflammation of your coronary and cardiovascular system caused by heart disease can be a reason why levels of monocytes are above the normal range.

Researchers from the American Heart Association say that cardiovascular disease encompasses many health conditions related to your heart and arteries. These include symptoms of angina, heart attacks, stroke, venous thrombosis, or high blood pressure.¹⁸ Very often inflammation is connected with cardiovascular disease due to a buildup of cholesterol in the blood vessels.¹⁹

The journal Biomarker Research reported that increased monocytes are often seen in blood test results of patients who have some form of cardiovascular disease. This is connected with inflammatory responses in the arteries as the body tries to heal tissue damage.²⁰

There are some simple lifestyle changes to reduce your risk of cardiovascular disease. Because your heart is located on your left side, you should never ignore squeezing left-sided chest pain that spreads to your arm.

Rheumatoid arthritis

Increased or decreased monocytes could be a sign of inflammatory joint conditions like rheumatoid arthritis.

Scientists have found that the increase in monocyte levels due to inflammation happens as more white blood cells are produced to repair damaged tissue. This can result in a persistently high monocyte blood count as the immune system tries to combat chronic inflammation.²⁰

Inflammatory bowel disease

High levels of monocytes in a blood test may show up if you have inflammatory bowel disease (IBD). Crohn’s disease and ulcerative colitis are 2 examples of inflammatory conditions that affect the digestive tract.

The Journal of Clinical Pathology reported that ulcerative colitis causes abnormally high monocyte levels as well as increased differential white cell count. In cases of Crohn’s disease, monocyte levels were only slightly above the normal range.²¹

Some of the symptoms of IBD include a leaky anus, pain under your right rib cage, and a grumbling stomach. Inflammatory bowel disease can be difficult to manage. However, incorporating in your diet foods that reduce inflammation can help to reduce the symptoms of IBD.

Obesity

People who are overweight may see that they have high absolute monocytes in their blood test lab results.

According to the journal Cell Metabolism obesity can put a person at greater risk of developing diabetes. This can affect the bone marrow and result in an increased number of monocytes being released. Scientists discovered that losing weight helped to lower absolute monocyte count.²²

Also, the journal Aging Cell reported that high-fat diets increase inflammation in the body. This results in an overactive immune response and can mean that there are higher levels of monocytes in the blood.²³

You can easily find out if you are overweight for your age and height by using this BMI calculator. If you need to lose weight quickly, you should make sure and stay away from foods that cause belly fat.

Hodgkin’s disease and lymphoma

Hodgkin’s disease is a type of lymphoma that can cause monocytes levels to be higher than the normal range. Of course, a high monocyte count in a blood test doesn’t mean that you have a cancerous condition like lymphoma, because most cases of elevated monocytes are connected with infection or inflammation.

According to the Mediterranean Journal of Hematology and Infectious Diseases, Hodgkin lymphoma causes changes in the white blood cell count. This causes a high number of white blood cells, including an increase in relative or absolute monocyte count.²⁴

What to Do if Mono Levels are Low or High

Many people wonder how they can make monocyte levels normal and treat the symptoms of high or low monocytes. Most of the time, it’s necessary to address the underlying condition to normalize mono levels. However, there are some ways that you can increase or normalize mono levels.

Get active to increase monocyte levels

Physical activity can help to address many of the underlying causes of inflammation that cause a rise in monocytes levels. Regular exercise helps to keep your heart healthy and prevent cardiovascular disease. Also, exercising 3 or 4 times a week can help to shed extra pounds quickly and reduce inflammatory responses in the body.

According to the journal Biology of Sport, increased physical activity has a positive effect on normalizing monocyte levels. Exercise can help to increase monocytes and other white blood cells in the recovery phase after exercising.²⁵

Vitamin B12

If anemia or a vitamin B12 is to blame for an abnormal monocyte count, then supplementing your diet with vitamin B12 can help to address the symptoms of anemia.

The Central European Journal of Immunology reported that vitamin B12 supplements are effective for persons who have a low-protein diet. B12 supplementation can help to normalize monocyte levels and also boost the immune system at the same time.²⁶

Vitamin C

It is known that vitamin C is essential for a healthy immune system and to help fight off various infections.

The American Society of Hematology published a scientific study on the effect of vitamin C on monocytes. It was found that vitamin C prevented monocytes being destroyed too early and this helped to boost the health of the immune system.²⁷

Moderate alcohol intake

The overuse of alcohol is one of the habits that can damage your liver. However, some research points to the fact that moderate alcohol consumption can have a positive effect on monocyte levels.

The Journal of Immunology reported that moderate use of alcohol has beneficial cardiovascular effects. Of course, chronic alcohol consumption leads to inflammation and can cause abnormal monocytes levels. However, the study found that limited amounts of alcohol can help to reduce inflammatory responses in the body.²⁸

Garlic

Garlic is a wonderful medicinal herb that has antibacterial properties and can give your immune system a well-needed boost. Garlic also has a positive effect on your hemoglobin concentration and white blood cell count.

The African Journal of Biomedical Research found that increasing the amount of garlic in the diet helps to boost the number of monocytes, neutrophils, and lymphocytes.

There are many ways that you can use garlic as a medicine to cure many ailments. For example, you can make a natural cough syrup using garlic to cure chest infections. There is even research showing that increased garlic intake can help prevent some cancers.

Omega 3 supplements

Omega 3 supplements can help to reduce inflammatory responses in the body and help prevent various cardiovascular diseases. Research into the effect of omega 3 on reducing inflammation has shown positive results.

For example, the journal Experimental & Clinical Cardiology reported that omega 3 supplements help regulate monocyte adhesion. This has a positive effect on inflammatory responses and can help to reduce instances of heart disease and heart attack.²⁹

Read my other related articles:

• Leukocytes in Urine and Stool – Causes and Possible Solutions
• Low Lymphocyte Count (Lymphocytopenia) – What Does It Mean?
• Immature Granulocytes (IGs): What They Are and What IG Count Means

Medical Sources