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Head Circumference Measurement (Peripheral Blood Donor Screening)

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

This test measures the circumference of a donor’s head as part of a routine screening process for blood donation. It helps ensure compatibility and safety for recipients.

Quick summary

["A simple head measurement to support safe blood donation."]

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

Key facts at a glance

LOINC
111897-5
Short code
Head diameter PD Endscpy
Synonyms
Head diameter PD Endscpy
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
endoscopy
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 Is Done

Healthcare providers may request this test during blood donation screening to assess overall health, physical condition, and suitability for donation. While head circumference alone isn’t a diagnostic test, it can be part of a broader evaluation for conditions like anemia, malnutrition, or other systemic health concerns.

How the Test Works

A trained professional uses a measuring tape to wrap around the donor’s head at the widest point (typically just above the eyebrows). The measurement is recorded in centimeters and may be compared to standard reference ranges for age and gender.

What to Expect Before the Test

There are no special preparations needed. You’ll simply stand still while the staff member takes the measurement. This is a quick, non-invasive procedure with no discomfort.

What to Expect During the Test

The process is quick and painless. No blood draw or additional procedures are involved beyond the head measurement itself.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

What does a head circumference test measure?
It measures the donor’s head circumference at the widest point, often used as part of a broader health assessment for blood donation eligibility.
Is this test painful or uncomfortable?
No, this test is completely painless and involves only a brief measurement with a tape measure.
Can abnormal results affect my ability to donate blood?
Abnormal measurements may require further evaluation by a healthcare provider, but they don’t automatically disqualify you from donating unless other criteria (like health history) are also considered.
  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