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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 that helps fight infections and inflammation in your body.

Quick summary

["Monocytes help protect your body by responding to infections and tissue damage."]

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

Key facts at a glance

LOINC
68423-3
Short code
Monocytes NFr Vitf Manual
Synonyms
Monocytes NFr Vitf Manual
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Is a Monocyte Count Test Used For?

Doctors may order a monocyte count test to check for infections, inflammatory conditions, or certain blood disorders. It can also help monitor treatment responses in conditions like leukemia or autoimmune diseases.

When Might You Need This Test?

You might need this test if you have symptoms like fever, fatigue, unexplained weight loss, or if your doctor suspects an infection, inflammation, or blood-related condition. It’s also used during routine check-ups for certain chronic illnesses.

How Is the Test Performed?

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

What Do the Results Mean?

Results show the number of monocytes in your blood. High or low counts can signal different health issues, so your doctor will interpret the results in the context of your overall health and symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Monocyte counts can be elevated in infections, chronic inflammation, or certain cancers like leukemia. Low counts may indicate immune deficiencies or other blood disorders. Always discuss results with your healthcare provider.

Short name

Monocyte Count

Frequently asked questions

Why might my doctor want to check my monocyte count?
Your doctor may check your monocyte count to diagnose or monitor conditions like infections, autoimmune diseases, or blood disorders. It can also help guide treatment decisions.
What are typical reference ranges for monocyte counts?
Reference ranges vary by lab and individual health. Your doctor will provide your specific results and explain what they mean for you.
Can I eat or drink anything before this test?
No special preparation is usually needed, but follow any instructions your doctor gives you, such as fasting or avoiding certain medications.
  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