Heavy Metals Panel Updated May 1, 2026

Mercury (Hg)

Mercury (Hg) is a toxicology lab value used to measure mercury exposure in the body. On a lab report, Hg usually refers to a blood, urine, or other specimen measurement reported by mass concentration.

Part of the Heavy Metals Panel — see all 3 values together, including Lead, Arsenic.

What Mercury (Hg) Measures

Mercury (Hg) is a lab value that measures the amount of mercury in a specimen, most often blood or urine. On a lab report, Hg reflects exposure to this metal and how much is present at the time of testing. In a toxicology panel, Mercury on a lab report is read as an exposure marker rather than a routine blood-composition value.

Why Hg Appears on Toxicology Panels

Mercury (Hg) is usually included on a toxicology panel when exposure to mercury is being checked or tracked over time. An Hg test may be ordered with other exposure markers in a broader toxicology workup, and Mercury on a blood test can help show whether a recent exposure is present. It is not part of a routine CBC or CMP.

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Mercury Reference Range by Specimen

Group Range Unit
Adult Male 0–10 µg/L
Adult Female 0–10 µg/L

Reference ranges may vary by laboratory and individual factors.

What High Hg Suggests in Toxicology

High Hg generally means more mercury was measured than expected for that specimen type. For blood Hg, values above common adult reference cutoffs such as 10 µg/L are often considered high, while urine ranges use different units and cutoffs. Mercury test result interpretation depends on whether the sample is blood, urine, or another matrix.

Associated factors

Recent seafood intake — some foods can temporarily raise blood Hg after a meal.
Occupational exposure — work around metal processing, mining, or instrument handling can increase measured Hg.
Dental materials — certain older dental materials can contribute to low-level mercury exposure.
Indoor air exposure — inhaled vapor can raise blood Hg more directly than many other routes.
Skin or product exposure — some imported creams or products may contain mercury compounds.
Ongoing environmental exposure — repeated contact can keep Hg readings above the Mercury normal range.
Specimen type — blood and urine detect different forms of Hg and can look high for different reasons.
Timing of collection — a recent exposure can make a Hg test read higher than an older one.

What Low Hg Means on a Report

Low Hg usually means little mercury was detected in the specimen. For a toxicology lab, that is generally expected when exposure is minimal or remote. A low Mercury test result is usually interpreted as a low exposure reading, not as a sign of blood composition change. On a blood test, low Hg is often simply below the reporting threshold or within the Mercury normal range.

Associated factors

Minimal exposure — little recent contact keeps measured Hg low.
Time since exposure — levels can fall as mercury clears from blood or urine.
Specimen type — a urine Hg test may read low even when a blood sample is higher, and vice versa.
Diet pattern — low intake of mercury-containing foods can keep values low.
No occupational contact — absence of workplace exposure often keeps Hg near baseline.
Chelation or detox products — some interventions may lower measured Hg in specific contexts, though lab methods vary.
Lab reporting limit — values under the assay limit may appear as low or undetectable.
Hydration status — more dilute urine can reduce a urine Hg concentration.

Hg With Pb, As, and Cd

Mercury (Hg) is often read alongside lead (Pb), arsenic (As), and cadmium (Cd) in a toxicology panel. These markers together help describe different exposure patterns because each metal has its own common sources and specimen behavior. When Hg is compared with blood or urine creatinine, the creatinine result can help interpret how concentrated a urine sample is. Mercury on a blood test is also sometimes reviewed with other toxicology markers to see whether a single source or multiple exposures may be present.

What Shifts Hg Test Results

Age, sex, and body size can shift Hg slightly because reference intervals and specimen distribution differ across people. Diet can matter, especially seafood intake, since some foods can raise Hg temporarily. Hydration affects urine Hg concentration, while recent exercise can change how concentrated a sample appears. Time since a mercury exposure is important because blood Hg and urine Hg may fall at different rates. Lab method also matters, since different assays and specimen types use different reference limits.

How Labs Measure Hg

Mercury is measured from a blood, urine, or sometimes hair specimen, depending on the panel and the question being asked. The lab reports Hg in units such as µg/L, µg/dL, or µg/g creatinine for urine, depending on the method and specimen type.

Prep Notes for a Hg Test

No fasting is usually required for a Mercury test, but specimen type matters because blood and urine Hg are not read the same way. The lab order often specifies whether the Hg test is for blood, urine, or another matrix.

Hg Test Questions

What is a normal Hg level?
A normal Hg level depends on the specimen, but blood mercury is often referenced as less than about 10 µg/L in adults. Urine Hg uses different units and different cutoffs, so the Mercury normal range is not one universal number. On a Mercury test result, the lab usually lists its own reference interval next to the value.
What does Hg stand for?
Hg is the chemical symbol for mercury. On a blood test or toxicology panel, Hg usually labels the mercury measurement rather than another blood component. The abbreviation is used because it is the standard symbol for the element in lab reporting and chemistry.
What does high Hg mean on a lab report?
High Hg means the measured mercury value is above the lab’s reference interval for that specimen. In a toxicology setting, that usually reflects greater recent or ongoing exposure, but the meaning depends on whether the sample is blood, urine, or another matrix. The same Mercury test result can look different across specimen types because they capture different forms of Hg.
What does low Hg mean on a lab report?
Low Hg means little mercury was detected, or the value falls near the lower end of the lab’s reporting range. For a toxicology panel, that is often expected when exposure is limited or remote. Low Hg is usually read as a low exposure finding rather than a separate medical category.
What causes high Mercury?
High Hg is often linked to recent seafood intake, occupational contact, environmental exposure, or products that contain mercury compounds. The specimen type matters because blood Hg and urine Hg reflect different exposure windows and different mercury forms. A high Mercury on a lab report can also result from timing, since a recent exposure may show up more strongly than an older one.
Can hydration or diet affect Mercury?
Yes. Diet can affect Hg, especially when seafood intake is recent, and hydration can change urine concentration enough to alter a urine Mercury test result. Blood Hg is less affected by hydration than urine Hg, but specimen timing still matters. These shifts are one reason the Mercury normal range is interpreted alongside the type of sample collected.
What is the difference between Mercury and lead?
Mercury (Hg) and lead (Pb) are different toxicology markers that reflect different metals and different exposure patterns. Mercury on a blood test is often used for recent exposure, while lead is commonly read with its own reference interval and specimen behavior. They may appear together on a toxicology panel, but they are not interchangeable.
What unit is Mercury measured in?
Mercury is commonly measured in µg/L, µg/dL, or µg/g creatinine, depending on whether the specimen is blood or urine. The unit on the report is important because a Mercury test result cannot be compared across specimen types without considering the unit. Some labs also report Hg as a whole-number concentration with the reference interval beside it.
How much can Hg change between tests?
Hg can change noticeably between tests if the exposure pattern, specimen type, or timing changes. Blood Hg may shift after recent intake or exposure, while urine Hg may vary more with hydration and collection timing. Small changes can fall within normal analytic and biologic variation, so the Mercury normal range is only one part of the comparison.
Is Hg different for men and women?
For many toxicology reference intervals, Hg is not strongly separated by sex the way some other lab values are. Some labs still list the same Mercury normal range for adult men and adult women, while others may use method-specific or specimen-specific cutoffs. The report’s own interval is the most relevant frame for a Mercury on a blood test.
What does Hg on a blood test mean?
Hg on a blood test means the lab measured mercury in the blood specimen. It is a toxicology value, so it mainly reflects exposure and how much mercury is present at the time of collection. The number should be read with the specimen type and unit, because blood Hg and urine Hg are not interpreted the same way.

Disclaimer

This content is for informational and educational purposes only. It is not intended as medical advice, diagnosis, or treatment recommendation. Reference ranges may vary by laboratory. Always discuss your results with a qualified healthcare professional.

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