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Serum or plasma concentration of homocysteine

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

This test measures the amount of homocysteine, a type of amino acid, in your blood. It helps assess risks related to heart disease, nerve damage, or other health conditions.

Quick summary

["Homocysteine levels can indicate potential risks for vascular or neurological complications."]

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

Key facts at a glance

LOINC
39889-1
Short code
NM Hrt FP+EF W RNC IV
Synonyms
NM Hrt FP+EF W RNC IV
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
nm
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 Is This Test Done?

Your healthcare provider may order this test if you have symptoms or risk factors for conditions like heart disease, stroke, or nerve damage. It may also be checked during evaluations for genetic disorders or as part of routine cardiovascular screening.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves a blood draw, but this depends on your provider’s instructions. Avoid smoking or consuming alcohol for 24 hours before testing.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. The sample is then sent to a lab for analysis. The test typically takes a few minutes, and you may feel slight discomfort but no lasting effects.

What the Results Mean

Results are compared to general reference ranges, but individual values can vary based on age, sex, and health status. High levels may signal increased risk for vascular issues, while low levels are less commonly associated with concerns.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Homocysteine Level

Frequently asked questions

What causes elevated homocysteine levels?
Elevated homocysteine can result from genetic factors, poor nutrition (low intake of folate, vitamin B6, or B12), kidney disease, certain medications, or metabolic disorders. Lifestyle factors like smoking or alcohol use may also contribute.
How can I lower my homocysteine levels if they’re high?
Focus on a balanced diet rich in folate (leafy greens, beans), vitamin B6 (nuts, whole grains), and vitamin B12 (meat, eggs, fortified foods). Regular exercise, avoiding smoking, and managing conditions like diabetes or kidney disease may also help.
Do I need to repeat this test if my levels are borderline?
Yes, your provider may recommend retesting after lifestyle changes or if symptoms persist. Repeat testing helps track trends and ensure your approach is effective.
  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