Does this test have other names?
What is this test?
This test measures the amount of mercury in your blood.
Mercury is a heavy metal that can be toxic. It occurs naturally as a liquid at room
temperature and as an odorless vapor.
You can be exposed to mercury from polluted air or water. You can also be exposed if
you work in an industry that still uses mercury, from eating fish that are high in
mercury, and from some complementary and alternative health remedies.
Long-term exposure to mercury can cause kidney and brain damage in adults. Exposure
to mercury during pregnancy can cause permanent damage to the developing fetus. Breastfeeding
may also expose infants to mercury.
Children who are exposed to mercury can suffer damage to their kidneys, nervous system,
and digestive system.
Mercury is also in silver amalgam dental fillings. Tiny amounts of mercury may be
absorbed from these fillings, but this amount is not likely to cause health problems.
Why do I need this test?
You may have this test if your healthcare provider suspects that you have mercury
poisoning. Symptoms include:
Shortness of breath
Inhaling mercury can cause:
You may also need this test to monitor your safety if it's possible that you could
be exposed to mercury at your work.
You may also have this test if you are pregnant or breastfeeding and have been exposed
to high levels of mercury.
What other tests might I have along with this test?
Your healthcare provider may also order tests of your urine or breastmilk to measure
for mercury. He or she may also test hair from your scalp to measure mercury exposure.
What do my test results mean?
Many things may affect your lab test results. These include the method each lab uses
to do the test. Even if your test results are different from the normal value, you
may not have a problem. To learn what the results mean for you, talk with your healthcare
The results of this test are given in nanograms per milliliter (ng/mL). Having some
mercury in your blood does not mean you will develop health problems.
Here is the breakdown on higher results:
5 ng/mL: This may mean you are being exposed to unhealthy levels of mercury at your
work or in your diet.
30 to 40 ng/mL: This level usually causes some symptoms and some brain or kidney damage.
Above 100 ng/mL: This is considered mercury poisoning.
How is this test done?
The test requires a blood sample, which is drawn through a needle from a vein in your
Does this test pose any risks?
Taking a blood sample with a needle carries risks that include bleeding, infection,
bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight
stinging sensation or pain. Afterward, the site may be slightly sore.
What might affect my test results?
Certain Chinese herbal products or skin-lightening creams that contain mercury can
cause your blood level to rise. Eating fish and shellfish that contain high levels
of mercury can raise your mercury levels.
How do I get ready for this test?
You don't need to prepare for this test.