Monocyte count (qualitative assessment of cell morphology in peripheral blood smear)
This test examines the appearance and quantity of monocytes in your blood sample under a microscope. Monocytes are a type of white blood cell that help fight infections and inflammation.
["This qualitative review helps doctors assess immune function and detect abnormalities in white blood cell counts."]
Key facts at a glance
- LOINC
- 72344-5
- Short code
- Monocytes/Rnd cells NFr Prost fld Manual
- Synonyms
- Monocytes/Rnd cells NFr Prost fld Manual
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0
- Ref high
- 20
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- manual-count
- CPT
- 85651
- 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 This Test Measures
The test looks at the presence and shape of monocytes, which are a subtype of white blood cells. Monocytes can appear as large cells with a single nucleus and sometimes visible granules. The test may also note if there are unusual numbers or shapes that could indicate health concerns.
Why It’s Done
Doctors may order this test if you have symptoms like frequent infections, unexplained fatigue, or signs of inflammation. It can also be part of a general blood check or when investigating conditions like leukemia, immune disorders, or chronic infections.
Sample Collection and Preparation
A small blood sample is drawn from your arm, typically using a needle. The sample is then spread thinly on a microscope slide and examined under a high-powered lens. This process allows healthcare providers to count and assess the appearance of each cell type, including monocytes.
What to Expect Before the Test
There are no special preparations needed for this test. You may have a slight bruise or slight discomfort at the injection site, but this usually fades quickly. If you’re on blood-thinning medication, let your doctor know before the test.
Reference range
Adult males: 0-15 mm/hr; Females: 0-20 mm/hrN/A
No special preparation required. CRP may be affected by acute illness.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal monocyte counts or shapes can signal underlying health issues. For example, an increased number of monocytes (monocytosis) might suggest chronic infections, inflammation, or certain cancers. A decreased count (monocytopenia) could indicate immune suppression or bone marrow disorders. Always discuss results with your healthcare provider, as they’ll consider your full medical history and symptoms.
Frequently asked questions
How long does it take to get results?
What does a normal monocyte appearance look like?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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