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Mercury (Urine)

Does this test have other names?

Hg urine

What is this test?

This test measures the amount of mercury in your urine.

Mercury is a heavy metal that can be toxic. There are three forms of mercury that can cause different symptoms if taken internally through diet, inhalation, or when applied to the skin. Mercury exists 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 need this test if your healthcare provider suspects that you have mercury poisoning. Symptoms include:

  • Fever

  • Chills

  • Chest tightness

  • Shortness of breath

Inhaling mercury can cause:

  • Nausea

  • Diarrhea

  • Vomiting

  • Burning sensation in your mouth

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 might also have this test if you are having chelation therapy for mercury poisoning. Chelation is a treatment that flushes out and removes toxins from your body. This test finds out whether the treatment is working.

What other tests might I have along with this test?

Your healthcare provider might also order a test to measure mercury levels in your blood. He or she may also test hair from your scalp to measure mercury exposure.

What do my test results mean?

Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. 

Results are given in nanograms per milliliter (ng/mL). Urine levels of mercury less than 20 ng/mL are considered safe.

Having some mercury in your urine doesn't mean you will develop health problems.

High levels of mercury in your urine could mean that you have mercury poisoning and need treatment.

How is this test done?

The test is done with a urine sample. Your healthcare provider will tell you how to collect a sample in a sterile container.

This test may use a 24-hour urine sample. For this sample, you must collect all of your urine for 24 hours. Empty your bladder completely first thing in the morning without collecting it. Note the time. Then collect your urine every time you go to the bathroom over the next 24 hours.

Does this test pose any risks?

This test poses no known risks.

What might affect my test results?

Certain medicines and skin-lightening creams that contain mercury can cause your mercury levels 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. Be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use. 

Medical Reviewers:

  • Freeborn, Donna, PhD, CNM, FNP
  • Haldeman-Englert, Chad, MD