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Annual Mercury Level (Serum)

Published: August 9, 2026Updated: August 10, 2026

This test measures the amount of mercury in your blood to check for exposure to this heavy metal, which can affect your health over time.

Quick summary

Helps detect potential mercury poisoning from environmental or occupational sources.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 10, 2026Editorial policy

Key facts at a glance

LOINC
66449-0
Short code
MRVARE
Synonyms
Annual mercury (rMer a) 1 IgE Qn
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or red-top clot activator tube
Units
N/A
Ref low
0
Ref high
0.35
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
Fluorescent Enzyme Immunoassay (FEIA) / ImmunoCAP
CPT
86003
SNOMED
395790002
Specimen volume
0.5-1.0 mL serum (minimum 0.3 mL)
Stability
Stable at room temperature for 8 hours; refrigerated (2-8°C) for 7 days; frozen (-20°C or below) for up to 1 year. Avoid repeated freeze-thaw cycles.
Hemolysis max
500
Lipemia max
1000
Icterus max
100
TAT
24–72 hours
Order
routine

Why This Test Matters

Mercury is a toxic substance found in some industrial products, certain foods (like fish), and even household items like thermometers. High levels in your blood can lead to health problems, especially if you’ve been exposed to it regularly. This test helps doctors monitor your risk and guide treatment if needed.

What to Expect Before the Test

No special preparation is usually required, but you may be asked to fast for 8–12 hours before the test if your blood is drawn from a vein. Wear comfortable clothing and bring any medications you’re currently taking, as some may affect results.

What the Test Involves

A healthcare provider will take a small blood sample from your arm using a needle. The sample is then sent to a lab for analysis. The process takes about 15 minutes total, and you may feel a slight pinch but no lasting discomfort.

What the Results Mean

Results are typically reported as a concentration of mercury in the blood. While exact reference ranges vary by lab, very high levels may indicate recent or chronic exposure, while very low levels suggest minimal risk. Your doctor will interpret results in the context of your health history and exposure.

Reference range

<0.35 kU/L: Negative (undetectable allergen-specific IgE); 0.35-0.70 kU/L: Equivocal/Low; 0.70-3.50 kU/L: Moderate; 3.50-17.50 kU/L: High; >17.50 kU/L: Very High. Reference ranges vary by laboratory and assay platform.N/A

Specimen: serum

No special preparation required. Patient should inform provider of all medications, including antihistamines, which may not need to be discontinued for IgE testing as they do not affect antibody levels. Avoid collecting during active allergic episodes if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Chronic exposure to mercury can damage the nervous system, kidneys, and immune function. In children, it may affect brain development. Acute exposure (e.g., from a mercury spill) can cause immediate symptoms like nausea, headache, or neurological issues. This test helps identify exposure risks so doctors can recommend lifestyle changes, dietary adjustments, or medical support if needed.

Short name

Mercury Blood Test

Frequently asked questions

How often should I get this test?
The frequency depends on your risk factors. If you work in industries with mercury exposure (e.g., mining, electronics manufacturing) or consume high-mercury foods regularly, your doctor may recommend testing every 1–3 years. Otherwise, this test is usually not routine unless you have symptoms or concerns.
What does a high mercury level mean?
A high level suggests recent or ongoing exposure. Your doctor will assess whether it’s due to environmental, occupational, or dietary sources. They may recommend reducing exposure, chelation therapy (in severe cases), or further testing to pinpoint the cause.
Can diet affect mercury levels?
Yes. Eating fish high in mercury (e.g., swordfish, king mackerel) or certain seafood can raise levels. Avoiding these foods or eating low-mercury alternatives (like salmon or sardines) may help lower your mercury exposure over time.
  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 10, 2026. · Read our editorial policy