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Monocyte Count (Peripheral Blood)

Published: August 9, 2026Updated: August 16, 2026

This test measures the number of monocytes, a type of white blood cell, in your blood. Monocytes help fight infections and remove dead cells or debris.

Quick summary

["Monocyte count helps assess immune function and detect potential infections or inflammatory conditions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
743-5
Short code
Monocytes # Bld Manual
Synonyms
Monocytes # Bld Manual
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Doctors may order a monocyte count to evaluate symptoms like persistent fevers, unexplained infections, or signs of chronic inflammation. It can also help diagnose conditions like leukemia, autoimmune diseases, or certain infections.

What Does the Test Involve?

A small blood sample is taken from a vein, usually in your arm. The sample is then analyzed in a lab to count the number of monocytes present.

What Are Normal Results?

There are no specific numeric reference ranges provided here since they vary by lab. Your results will be compared to your lab’s standards and discussed with your healthcare provider.

What Might Abnormal Results Mean?

High monocyte counts may indicate chronic infections, inflammation, or certain cancers. Low monocyte counts could suggest immune deficiencies or other underlying health issues. Your healthcare provider will interpret results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Monocyte count is crucial for diagnosing and monitoring conditions affecting the immune system. Elevated levels may signal ongoing inflammation or infection, while decreased levels could point to weakened immune function or specific disorders requiring further investigation.

Short name

Monocyte Blood Count

Frequently asked questions

How often should I expect to have this test?
The frequency depends on your health condition and doctor’s recommendations. Some patients may need this test regularly if they have chronic illnesses like autoimmune diseases or cancer.
What lifestyle or dietary changes can affect monocyte counts?
Certain infections, stress, or chronic illnesses can temporarily alter monocyte levels. However, diet and exercise generally do not directly impact monocyte counts unless they affect overall immune health.
Can I eat or drink before this test?
Typically, you can eat and drink normally unless your doctor specifies otherwise. Avoiding alcohol or certain medications may be advised, so check with your healthcare provider beforehand.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy