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Serum or plasma concentration of homocysteine

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

This test measures the amount of homocysteine, an amino acid that can build up in your blood and may increase your risk of certain health problems.

Quick summary

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

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

Key facts at a glance

LOINC
49775-0
Short code
HDV IgG Ser IA-aCnc
Synonyms
HDV IgG Ser IA-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
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 Homocysteine?

Homocysteine is a non-essential amino acid produced during the breakdown of proteins. Normally, your body converts it into other substances, but when levels rise too high, it may damage blood vessels and increase the risk of cardiovascular conditions like heart disease or stroke.

Why Might This Test Be Ordered?

Your healthcare provider may order this test if you have a family history of heart disease, stroke, or blood vessel problems, or if you have conditions like kidney disease, diabetes, or certain genetic disorders that affect how your body processes homocysteine.

What Does a High or Low Level Mean?

High levels of homocysteine may signal an increased risk of vascular damage, though results alone don’t diagnose a specific condition. Low levels are less commonly associated with clinical concerns unless linked to other health factors.

How Is This Test Performed?

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab where it is analyzed using an immunoassay method to measure homocysteine concentration.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Homocysteine Level

Frequently asked questions

What Are the Normal Homocysteine Levels?
Normal ranges can vary by lab and individual, so your results will be interpreted in the context of your overall health. High levels may warrant further evaluation for underlying causes like vitamin deficiencies or genetic factors.
How Often Should I Get This Test?
Your provider will determine how often to check this test based on your health status, risk factors, and medical history. Regular monitoring may be recommended if you have conditions like heart disease or kidney problems.
Can I Take Anything Special Before the Test?
Avoid excessive alcohol, certain medications (like folic acid or vitamin B supplements), or smoking for 24 hours before the test, as these may affect results. Follow your provider’s instructions for fasting if required.
  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