From the blog
Heavy Metal Test: Which Sample Suits Which Metal, and What a Result Means
In short: A heavy metal test measures a metal such as lead, mercury, arsenic or cadmium in a blood or urine sample. Sample choice depends on the metal, its form and exposure timing: blood for lead, urine for arsenic, urine or blood for cadmium, and blood or urine for mercury. A result only means something when it is read with your exposure history. Provoked urine tests are not recommended.
What is a heavy metal test?
A heavy metal test is a laboratory test that measures how much of a toxic metal is in your blood or urine. It is not one single test. A doctor chooses which metals to measure and which sample to use, based on what you may have been exposed to.
Finding a metal does not by itself mean poisoning. Most people carry small amounts picked up from food, water and air. What matters is how much, in which form, and whether it fits your symptoms and exposure.
Which metals are on a heavy metal test list?
Four commonly assessed toxic elements are lead, mercury, arsenic and cadmium. A 2026 review of these four sets out how each is usually measured:
Lead: a blood sample. A blood lead level from a vein is the main test. An elevated finger-prick lead result should be confirmed using venous blood because sample contamination can falsely raise it.
Mercury: blood or urine, depending on the form. Whole blood reflects recent exposure to methylmercury, the form found in fish, and to mercury vapour. Urine is a better measure of inorganic mercury, the form in some skin-lightening creams.
Arsenic: a urine sample with "speciation". Speciation means the laboratory separates the harmful inorganic forms from the far less harmful forms found in seafood. Seafood can raise total urinary arsenic without indicating poisoning. Speciation helps distinguish forms; when unavailable, repeat testing after seafood avoidance can help interpretation. Doctors usually ask you to avoid seafood for 48 to 72 hours before the test.
Cadmium: urine or blood. Urine helps assess long-term exposure; blood helps assess recent exposure. Kidney damage can alter urinary results, so kidney function also matters.
The review is a guide to how doctors think, not a rule for every case. Your doctor may also ask for a blood count and kidney and liver tests, to help assess possible effects.
Why are provoked urine tests not recommended?
Provoked urine tests are not recommended because they have no validated standard and no normal range. In this test, also called a challenge or mobilisation test, a chelating medicine is given first and urine is collected afterwards.
A review in the Journal of Medical Toxicology found that:
no standard, validated version of the test exists
agents, doses and collection methods all vary
results are often compared with reference ranges that do not apply to them
urine mercury rises after a chelating agent whatever a person's exposure history
the test failed to reveal a "body burden" from past mercury exposure
chelating agents have been linked to adverse reactions
The review concluded that these tests should not be used. Ask how any test you are offered was validated, and whether the sample was collected without a chelating agent.
How are people in India exposed to heavy metals?
The main routes in India are some traditional preparations, water, work, and everyday products. Your doctor will ask about each.
Ayurvedic and other traditional preparations. The concern is with particular preparations, not a whole system of medicine. In a study of 193 Ayurvedic medicines bought online, published in 2008, using products purchased in 2005, about one in five contained detectable lead, mercury or arsenic, and this was more common in rasa shastra products, which combine herbs with metals and minerals. At a hospital in Ludhiana, 75 of 786 patients tested for unexplained stomach pain had high blood lead, and 73 of those had taken Ayurvedic medicines. Bring every packet you take to your appointment. Do not stop a prescribed medicine without speaking to your doctor.
Water. Arsenic occurs naturally in groundwater in parts of India. A 2026 systematic review in the Indian Journal of Medical Research named Punjab, West Bengal, Haryana, Delhi, Uttarakhand, and Jammu and Kashmir among the affected regions. If you rely on a borewell, a water test by a laboratory can tell you more than a blood test about the source.
Work. The World Health Organization (WHO) lists smelting, recycling, and stripping leaded paint as sources of lead. Battery work and mining are also known routes. Cadmium is used in rechargeable batteries and pigments.
Food, tobacco and products. Large predatory fish can carry more methylmercury. Tobacco smoke is a significant source of cadmium. WHO warns that some skin-lightening products contain mercury, and that lead is found in some traditional cosmetics, ceramic glazes and paints.
Who should consider a heavy metal test?
Testing makes the most sense when there is a clear exposure or a long illness that has no other explanation. Examples are work with lead or batteries, long use of a metal-containing preparation, or drinking from a water source known to carry arsenic.
Symptoms alone are a weak guide. Tiredness, stomach pain, constipation and poor concentration have many other causes. Without any exposure history, a broad screen can produce numbers that are hard to interpret. Anyone who is pregnant or planning a pregnancy should mention any possible lead exposure to their doctor, because WHO notes that lead stored in bone can be released into the blood during pregnancy.
What should I do with a raised result?
First, do not panic, and do not start any "detox". Take the report to a doctor, who will usually work through these steps:
Confirm it. Check that the right sample was used and that it was collected correctly. Seafood can raise total arsenic, and a finger-prick sample can raise lead.
Find the source. This is the most useful step. WHO advises identifying and stopping the source of lead when blood lead is 5 micrograms per decilitre (µg/dL) or above. That figure is a signal to act on exposure, not a signal to start chelation.
Check for effects. Blood count, kidney and liver tests help assess possible effects; abnormalities alone cannot establish that a metal caused them.
Decide on treatment. Chelation, a medicine that binds metal so it can leave the body, is reserved for specific cases and needs medical supervision. Our chelation guide explains who may need it and its risks.
Retest at the right time. Levels fall at different speeds. The 2026 review suggests rechecking over weeks to months for mercury and lead, months to years for cadmium, and days to weeks for arsenic.
Sudden severe stomach pain, vomiting, confusion or seizures after a possible exposure need urgent hospital care.
How does a SOMA doctor decide which test is right for you?
SOMA's initial assessment includes toxin and heavy-metal screening among its diagnostic options; physicians select panels using your history. Bring your earlier reports and a list of your medicines and supplements, including any traditional preparations, and be ready to talk about your work, home and water.
SOMA's How We Do It page describes this screening as relevant for people with a long, unexplained illness or a high exposure history. What a result reveals depends on the sample, exposure timing and substance involved. Your doctor recommends it only where it makes sense for you. Results are explained in plain language and read together with the rest of your workup, as one part of a plan built around you.
SOMA centres in Mumbai and New Delhi
SOMA doctors see patients at two centres:
Mumbai: A-507, Kohinoor Square, N.C. Kelkar Marg, Shivaji Park, Dadar West, Mumbai 400028. Phone +91 98671 94033.
New Delhi: E-354, Greater Kailash II, New Delhi 110048, serving Delhi NCR and Gurugram. Phone +91 87969 92001. More about the New Delhi centre.
The New Delhi centre is independently operated under licence from SOMA Longevity Sciences, and its own doctors lead care there. Both centres follow the same SOMA assessment and diagnostic standards. Online consultations are also available. Contact either centre.
Questions people ask
What is a heavy metal test?
A heavy metal test measures a toxic metal such as lead, mercury, arsenic or cadmium in a blood or urine sample. A doctor chooses the metals and the sample based on your likely exposure, then reads the result alongside your history.
Is there a blood test for heavy metals?
Yes, for some metals. Blood is the main test for lead and for recent methylmercury exposure. Arsenic and inorganic mercury are usually better measured in urine. For cadmium, urine helps assess long-term exposure and blood helps assess recent exposure. One blood sample does not cover every metal equally well.
How do I prepare for a heavy metal test?
Tell your doctor about all medicines, supplements and traditional preparations. For a urine arsenic test, you will usually be asked to avoid seafood for 48 to 72 hours. Your laboratory will tell you whether it needs a single sample or a timed collection.
Should I take a chelating medicine before the test?
No. Provoked urine tests have no validated standard or normal range, and a review in the Journal of Medical Toxicology concluded they should not be used. Chelating agents have also been linked to adverse reactions.
Where can I get a heavy metal test in Mumbai or Delhi?
Start with a doctor who can match the test to your exposure. Doctors at SOMA's centres in Dadar West, Mumbai and Greater Kailash II, New Delhi review your history first, and then advise whether toxin and heavy-metal screening makes sense for you.
Related guides
Sources
Chakif D, Furrer J. Heavy metal toxicity in clinical and environmental health: sources, mechanisms, diagnostics, and evidence-based management of mercury, lead, cadmium, and arsenic. International Journal of Molecular Sciences 2026;27(8):3513. https://pubmed.ncbi.nlm.nih.gov/42074156/
Ruha AM. Recommendations for provoked challenge urine testing. Journal of Medical Toxicology 2013;9(4):318–325. https://pubmed.ncbi.nlm.nih.gov/24113861/
World Health Organization. Lead poisoning (fact sheet). https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health
World Health Organization. Mercury and health (fact sheet). https://www.who.int/news-room/fact-sheets/detail/mercury-and-health
World Health Organization. Arsenic (fact sheet). https://www.who.int/news-room/fact-sheets/detail/arsenic
Sakalkar V, Singh S, Gupta E, et al. Health risks of arsenic and chromium in groundwater and surface water in India: a systematic review. Indian Journal of Medical Research 2026;164(2):273–286. https://pubmed.ncbi.nlm.nih.gov/42555689/
Saper RB, Phillips RS, Sehgal A, et al. Lead, mercury, and arsenic in US- and Indian-manufactured Ayurvedic medicines sold via the Internet. JAMA 2008;300(8):915–923. https://pubmed.ncbi.nlm.nih.gov/18728265/
Mehta V, Midha V, Mahajan R, et al. Lead intoxication due to ayurvedic medications as a cause of abdominal pain in adults. Clinical Toxicology 2017;55(2):97–101. https://pubmed.ncbi.nlm.nih.gov/27957879/
This article is for education and general information. It is not a substitute for a medical consultation, diagnosis or treatment. Results vary by individual biology.
Wondering what your own results would show? Start with a conversation.