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Monocyte count (per microliter of blood)

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

This test measures the number of monocytes, a type of white blood cell that helps fight infection and inflammation in your body.

Quick summary

["Monocytes help your immune system respond to illness and injury."]

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

Key facts at a glance

LOINC
40537-3
Short code
Monocytes NFr DiafP Manual
Synonyms
Monocytes NFr DiafP Manual
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0
Ref high
10
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
CPT
82105
SNOMED
394971007
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

Why This Test May Be Ordered

Your doctor may order this test to check for infections, autoimmune diseases, or conditions that affect your immune system, such as leukemia or certain types of anemia. It can also help monitor treatment responses in chronic conditions like rheumatoid arthritis or inflammatory bowel disease.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or hand to draw blood. If you’re concerned about needles, let your healthcare provider know. Avoid eating or drinking for 2 hours before the test if instructed.

What Happens During the Test

Blood is collected in a tube and sent to a lab for analysis. Monocytes are counted under a microscope or via automated blood cell counter. The result is reported as the number of monocytes per microliter of blood.

What the Results Mean

Results are compared to a general reference range for healthy adults. Very high or very low levels may signal underlying health issues, but individual results depend on your medical history and symptoms.

Reference range

Normal: <10 ng/mLN/A

Specimen: serum

No special preparation required. For PSA, avoid sexual activity for 24-48 hours before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Monocyte level

Frequently asked questions

How long does it take to get my results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time.
Can I eat or drink before this test?
Check with your doctor or lab for specific instructions, but generally, no food or drink is required for 2 hours before blood collection unless advised otherwise.
Does this test require fasting?
No fasting is required for this test, but follow any general preparation instructions your healthcare provider gives you.
  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