Homocysteine Test
A blood test that measures homocysteine, an amino acid linked to B-vitamin levels and blood vessel health.
Quick Summary
To check for B12 or folate deficiency and some inherited conditions.
Homocysteine level.
Fasting may be advised.
Overview
High levels are often due to low B12 or folate.
Routine testing for heart risk isn't usually needed.
What It Measures
Homocysteine
Blood level.
How It's Performed
- 01
Preparation
Usually no special preparation unless your doctor advises.
- 02
Blood sample
A small amount of blood is taken from a vein in your arm.
- 03
Afterwards
Press on the spot; a small bruise is common.
Reference Ranges
Note: Normal ranges vary by laboratory. Consult your report for the specific reference used.
| Parameter | Typical Range (Adult) | Units |
|---|---|---|
| Homocysteine | 5–15 | µmol/L |
Interpreting Results & Next Steps
Discuss with Doctor
Normal ranges differ between laboratories; use the range on your report. Your doctor will explain what your result means and what happens next.
If values are High:
High levels can reflect B12 or folate deficiency.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Homocysteine Test(opens in a new tab) · MedlinePlus, US National Library of Medicine