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Calculated Erythrocyte Volume Deviation Index (from Patient-Calculated Data)

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

This test evaluates how consistently your red blood cells vary in size, using data provided by your healthcare team. It helps assess potential red blood cell abnormalities that may affect blood health.

Quick summary

["This index may help identify conditions affecting red blood cell size stability, such as certain blood disorders or chronic illnesses."]

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

Key facts at a glance

LOINC
111542-7
Short code
Erythrocyte vol deviation/IVol Patient Calc
Synonyms
Erythrocyte vol deviation/IVol Patient Calc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
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
Method
calculated
CPT
85041
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 This Test Measuring?

Erythrocyte volume deviation refers to the degree of variation in the size of your red blood cells (erythrocytes). Normally, red blood cells are fairly uniform in size. This test calculates how much they differ from a reference range, using data from your blood sample and clinical calculations. It’s not a standalone test but derived from other measurements (e.g., mean corpuscular volume, or MCV).

Why Might Your Doctor Order This Test?

Your doctor may request this calculated index if they suspect conditions like anemia (e.g., iron deficiency or pernicious anemia), thalassemia, or other blood disorders that can cause red blood cells to vary in size. It may also be used alongside other tests to refine diagnosis or monitor treatment progress.

How Is This Test Performed?

This is a **calculated** test, meaning your healthcare provider will use results from your blood sample (e.g., red blood cell counts, MCV, or hemoglobin) and clinical algorithms to derive the deviation index. No additional blood draw or special preparation is needed beyond standard blood testing.

What Does the Result Mean?

A result indicates how much your red blood cells differ in size compared to what’s expected. High deviation may suggest conditions like microcytic anemia (smaller cells) or macrocytic anemia (larger cells), while normal deviation suggests healthy red blood cell consistency. Your doctor will interpret results in the context of your overall health and other test results.

Reference range

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

Specimen: serum

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Erythrocyte volume deviation is not a standalone diagnostic test but can provide additional insight when combined with other blood tests. High variability may signal underlying blood disorders that require further evaluation (e.g., bone marrow tests, genetic screening). Doctors use this data to tailor treatment plans, such as adjusting medications (e.g., for iron deficiency) or monitoring chronic conditions like diabetes or kidney disease.

Short name

Erythrocyte Volume Variation Index

Frequently asked questions

What causes red blood cells to vary in size?
Red blood cell size variation can result from several factors, including deficiencies (e.g., iron, vitamin B12, or folate), chronic illnesses (e.g., kidney disease, liver disease), certain medications, or genetic disorders (e.g., thalassemia). Lifestyle factors like smoking or alcohol use may also play a role. If you notice fatigue, pale skin, or other symptoms, discuss these with your doctor.
How often will I need this test?
The frequency depends on your health status and treatment plan. Your doctor may order this test periodically if you have a diagnosed blood disorder, are undergoing treatment for anemia, or if they suspect changes in your red blood cells. Regular monitoring helps track progress and adjust care as needed.
Can I prepare for this test?
No special preparation is required for this calculated test. It’s typically performed as part of a routine blood draw, so you can eat and drink normally. If you have questions about your specific test results, ask your healthcare provider for personalized guidance.
  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