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Homocysteine (Serum or Plasma) Concentration

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

This test measures the level of homocysteine, an amino acid that plays a role in metabolism. Elevated levels may indicate an increased risk for certain health conditions.

Quick summary

["Homocysteine levels can help assess your risk for heart disease or blood vessel problems."]

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

Key facts at a glance

LOINC
50052-0
Short code
Hemicystine SFr DBS
Synonyms
Hemicystine SFr DBS
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 a family history of heart disease, stroke, or blood vessel issues, or if you have symptoms like fatigue, numbness, or weakness. It may also be checked in people with kidney disease or certain genetic conditions.

What Does the Test Involve?

A blood sample is taken from a vein in your arm. The blood is then sent to a lab where it is analyzed to measure homocysteine levels using a specialized immunoassay method.

What Do Results Mean?

Results are not typically provided as a single reference range since levels can vary based on factors like diet, genetics, and health conditions. Your provider will interpret the result in relation to your overall health and medical history.

Common Reasons for Testing

Elevated homocysteine levels might suggest an increased risk for vascular diseases, such as atherosclerosis (hardening of the arteries), or conditions like peripheral artery disease. Low levels may not indicate a problem but could be part of a broader evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Homocysteine Levels and Health Risks

Short name

Homocysteine

Frequently asked questions

What causes high homocysteine levels?
High homocysteine levels can be caused by genetic factors, certain medications (like some antidepressants or diuretics), kidney disease, vitamin deficiencies (such as folate or vitamin B12), or poor diet. Lifestyle factors, such as smoking or excessive alcohol use, may also contribute.
Can low homocysteine levels be harmful?
Low homocysteine levels are less commonly associated with health risks and are often found in people with certain genetic mutations or specific dietary patterns. However, they are not typically a cause for concern unless part of a broader clinical evaluation.
How often should I get this test?
The frequency of testing depends on your health status, risk factors, and medical advice. If you have conditions like kidney disease or a family history of vascular issues, your provider may recommend regular monitoring. Otherwise, it is usually not a routine screening test.
  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