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Red Blood Cell Area Measurement (RBC Area)

Published: August 9, 2026Updated: August 17, 2026

This test measures the average size of your red blood cells (RBCs) by analyzing their shape and area, which can help assess conditions affecting RBCs.

Quick summary

["Your RBC size may signal anemia, blood disorders, or other health concerns."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
105107-7
Short code
RBC #/area UrnS
Synonyms
RBC #/area UrnS
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Ref low
4.2
Ref high
5.9
Critical range
2 N/A – 7 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85041
SNOMED
900000000000003001
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Matters

Measuring RBC area helps doctors diagnose and monitor conditions like anemia (low RBC count) or conditions that cause RBCs to become too large or small. For example, certain types of anemia or blood disorders may lead to RBCs that are abnormally shaped or sized, which this test can detect.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. The test is quick and typically done in a lab.

Common Conditions Monitored

This test may be used to evaluate suspected conditions such as megaloblastic anemia (where RBCs are larger than normal), microcytic anemia (smaller RBCs), or other blood-related disorders.

How Results Are Interpreted

Results are compared to standard ranges for RBC size. Abnormal values may require further testing or follow-up to identify the underlying cause.

Reference range

Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A

Specimen: urine

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

RBC Area

Frequently asked questions

What does an abnormal RBC area mean?
An abnormal RBC area could indicate conditions like anemia (due to deficiencies like vitamin B12 or folate), certain blood disorders, or exposure to toxins. Your doctor will discuss results with you and may recommend additional tests if needed.
How often should I get this test?
Your doctor will determine how often this test is needed based on your health history, symptoms, and other test results. It may be part of routine blood checks or monitoring for specific conditions.
Can diet or lifestyle affect RBC area?
Yes, certain foods (like iron-rich foods) or deficiencies (such as vitamin B12 or folate) can influence RBC size. Lifestyle factors like smoking or chronic illness may also play a role. Always discuss your diet and health habits with your healthcare provider.
  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 17, 2026. · Read our editorial policy