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Homocysteine, Serum Concentration

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

This test measures the amount of homocysteine, a type of amino acid, in your blood serum. Homocysteine can be linked to certain health risks.

Quick summary

["Your homocysteine level helps assess your risk for heart disease and other vascular conditions."]

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

Key facts at a glance

LOINC
22715-7
Short code
(Hcys)2 Spec-sCnc
Synonyms
(Hcys)2 Spec-sCnc
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 history of heart disease, stroke, or other vascular conditions. It may also be used to monitor treatment for conditions like folate or vitamin B12 deficiency, which can affect homocysteine levels.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw blood, similar to other routine blood tests. If you’re on blood thinners, let your provider know before the test.

What the Results Mean

Homocysteine levels can vary based on diet, genetics, and other health factors. High levels may increase your risk for blood vessel damage, while low levels are less concerning unless related to a deficiency.

Common Causes of Abnormal Results

Elevated homocysteine levels may be caused by genetic factors, vitamin deficiencies (like folate or B12), kidney disease, or certain medications. Low levels can sometimes indicate deficiencies in these vitamins.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

High homocysteine levels are often associated with an increased risk of cardiovascular diseases, such as heart attacks and strokes. Your provider may recommend lifestyle changes, supplements, or further testing if levels are elevated.

Short name

Homocysteine Level

Frequently asked questions

What does a high homocysteine level mean for my health?
A high homocysteine level may suggest an increased risk of blood vessel damage or heart-related issues. Your doctor will discuss this with you and may suggest ways to manage it, such as dietary changes or supplements.
Can diet or supplements affect homocysteine levels?
Yes, diet and certain supplements (like folate, vitamin B6, and B12) can influence homocysteine levels. If your provider suggests changes, they may recommend specific foods or supplements to help lower levels.
Do I need to fast before this test?
No fasting is required for this test. Blood is drawn at a convenient time, and no special preparation is needed.
  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