Heavy metal testing
Lab testing for potentially harmful metals such as lead, mercury or arsenic
Also known as
Definition
Heavy metal testing measures the amount of potentially harmful metals in blood, urine, hair, nails, stool or tissue. The most commonly tested are lead, mercury, arsenic, cadmium and chromium, either individually or as a panel. Because heavy metals occur in the environment, in foods and in some medicines or supplements, small amounts in the body are normal. Blood and urine are the most commonly used samples.
| Parameter | Value |
|---|---|
| Unit | Depends on the metal and sample type; the unit is shown on your report |
| Reference Range | No single range: limits differ by metal, sample type (blood, urine, hair, nails) and laboratory. The reference range on your own report is what counts; your doctor evaluates the result. |
Agree on your personal target range with your doctor.
↓ What a low value means
Normal or low levels usually speak against heavy metal poisoning. However, some heavy metals leave the bloodstream quickly and are stored in tissues. If you have symptoms, further tests of urine, hair, skin or nails may follow. A normal blood result therefore does not rule out exposure in every case.
↑ What a high value means
Elevated levels can point to heavy metal poisoning, but not always. Follow-up tests are often done to confirm or rule out poisoning, along with checks of affected organs such as the kidneys. Even without symptoms, it may be necessary to avoid the source of exposure. Whether a treatment such as chelation therapy is appropriate is decided by your doctor, as it can have serious side effects.
When to test
Testing is ordered after possible exposure, for example at work in construction, battery manufacturing, plumbing or metal plating, or with symptoms such as nausea, abdominal pain, tingling in the hands and feet, muscle weakness or memory problems. Because some fish and shellfish contain high levels of mercury, you are advised to avoid seafood for 48 hours before the test. The sample type and collection method, such as 24-hour urine, are set by the practice.
Frequently asked questions
Which sample is most informative? +
It depends on the metal and the question being asked. Blood and urine are used most often. Hair, nails, stool or tissue may also be used depending on the metal, partly because some metals leave the blood quickly and are stored in tissues.
Is it normal to have heavy metals in the body? +
Yes, in small amounts. Heavy metals occur naturally in the environment, as well as in some foods, medicines and supplements. It becomes a problem when the amount is too high.
Is an elevated lab value already a diagnosis? +
No. Your doctor determines poisoning from the test result, symptoms and exposure history. Removal treatments such as chelation therapy belong in medical hands because they can have serious side effects.
Why should I avoid fish before the test? +
Some fish and shellfish contain high levels of mercury. That is why you are advised to avoid seafood for 48 hours before the test. Follow the instructions of your practice or laboratory.
Heavy metal testing
Last updated: October 05, 2026
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.