Red Blood Cell Morphology Examination (Peripheral Blood Smear Evaluation)
This test examines the shape and size of your red blood cells (RBCs) under a microscope. It helps identify abnormalities that may indicate conditions like anemia, blood disorders, or other health concerns.
["A smear test checks for unusual RBC shapes that could signal underlying health issues."]
Key facts at a glance
- LOINC
- 10376-2
- Short code
- Macrocytes Oval Bld Ql Smear
- Synonyms
- Macrocytes Oval Bld Ql Smear
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- microscopy-light
- 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 This Test Is Done
Your healthcare provider may order this test if you have symptoms like fatigue, pale skin, unusual bruising, or if they suspect conditions such as anemia, iron deficiency, or blood disorders. It’s also used to monitor treatment effectiveness or check for hidden blood problems.
What to Expect Before the Test
No special preparation is needed. A simple blood draw from your arm is all that’s required. The sample is spread thinly on a microscope slide for detailed examination.
What the Test Shows
The test looks at the size, shape, and appearance of your RBCs. Normal RBCs are usually round and uniform. Abnormal shapes, such as macrocytes (larger-than-normal cells), may suggest conditions like vitamin B12 deficiency, folate deficiency, or liver disease.
Common Findings and Their Possible Causes
Macrocytes (large RBCs) can appear on a smear if your body isn’t producing enough healthy RBCs. This may happen due to deficiencies in B vitamins (like B12 or folate), alcohol use, or certain medications. Other abnormalities, like microcytes (small RBCs) or poikilocytes (irregularly shaped RBCs), may also be noted.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Detecting macrocytes or other RBC abnormalities can help diagnose conditions like megaloblastic anemia, alcohol-related liver disease, or drug-induced blood disorders. Early identification can guide treatment plans, such as vitamin supplements or lifestyle changes.
Short name
Red Blood Cell (RBC) Smear Analysis
Frequently asked questions
What does a macrocyte on my smear mean?
Will I need to take any supplements if my smear shows macrocytes?
Can lifestyle changes help if my RBCs are abnormal?
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