Lab test
Magnesium, Urine Test
A magnesium urine test measures how much magnesium is being excreted in the urine.
- Typical price
- From $152
- Results
- 1-3 business days
- Preparation
- See preparation notes below
- Sample
- Blood draw or sample collection at a local center
About this test
A magnesium urine test measures how much magnesium is being excreted in the urine. It is often used alongside a blood magnesium test to help determine whether low magnesium is caused by poor intake or absorption, or by excessive loss through the kidneys. The test may be ordered when a provider is investigating persistent magnesium deficiency, kidney conditions, or the effects of medicines that influence magnesium handling. Because urine collection reflects magnesium output over time, the result is interpreted together with blood levels and clinical findings.
What this test measures
- Magnesium (urine) Measures the amount of magnesium excreted in urine.
- Magnesium (serum) Often measured alongside the urine test to compare blood and urine levels.
Who this test may be right for
- People with persistent or unexplained low magnesium
- Individuals being evaluated for kidney-related mineral loss
- People taking medicines that affect magnesium handling
- Those with symptoms such as cramps, weakness, or palpitations
Before your visit
- A timed or random urine collection may be requested; follow the given instructions.
- Tell the collector about magnesium supplements or diuretics you take.
- Follow any instructions provided for your specific panel.
Understanding your results
Urine magnesium helps show whether the kidneys are conserving or losing magnesium. High urine magnesium with low blood magnesium may point to kidney losses, while low urine magnesium may suggest inadequate intake or absorption. Results are interpreted with a blood magnesium level and your history. Discuss them with a healthcare provider.
Order this test online
- Buy online in a few minutes - no doctor's visit needed for most tests.
- Sample collection at a patient service center near you.
- Results are typically ready within 1-3 business days.
- Secure, lab-reviewed results delivered to your account.
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Questions people ask
Why test magnesium in urine instead of only blood?
A blood test shows the level circulating at one moment, while a urine test shows how much magnesium is being excreted. Comparing the two helps reveal the cause of an abnormal blood level.
How is a urine magnesium sample collected?
Depending on the request, a random sample or a timed collection may be used. The collection site will provide specific instructions to follow.
What does high urine magnesium mean?
It can indicate that the kidneys are excreting more magnesium than usual, which may occur with certain conditions or medicines. A provider interprets it with the blood level.
Can diuretics affect urine magnesium?
Yes. Some diuretics increase magnesium loss in urine, so tell the collector about all medicines you take.
What does the Magnesium, Urine Test measure?
Order Magnesium, Urine Test.com online through our partner and visit a local lab near you.
Do I need to fast before this test?
Follow the lab's instructions.
How long do results take?
Most Magnesium, Urine Test results are released in 1-3 business days. Specialty testing can take longer.
Is this test right for me?
This page is educational and not medical advice. Talk to a licensed healthcare provider about which tests fit your situation.
LabBookings is an independent directory. We compare test details and pricing information, but we are not a laboratory and we do not perform testing or provide medical advice. Always talk to a licensed healthcare provider about your results and treatment.
Laboratory services are provided by independent, CLIA-certified testing partners. Availability, pricing, and turnaround times can vary by location and are confirmed at checkout.