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Magnesium, Urine

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of magnesium, a mineral, found in your urine over a 24-hour period. It helps assess how well your body is excreting magnesium through urine.

Quick summary

["Urine magnesium levels can indicate kidney function and mineral balance."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
19124-7
Short code
Magnesium Ur-mCnc
Synonyms
Magnesium Ur-mCnc
Category
electrolyte
Sample
urine
Container
Sterile urine container
Units
N/A
Ref low
1.7
Ref high
2.2
Critical range
1 N/A – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
83735
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may order this test if they suspect conditions like kidney disease, metabolic disorders, or abnormal mineral levels in your body. It can also help monitor long-term kidney health or diagnose issues related to electrolyte imbalances.

What to Expect Before the Test

You’ll typically need to collect all urine produced over a full 24-hour period in a special container. Drink plenty of fluids during this time to ensure accurate results. Follow your provider’s instructions carefully to avoid missing any urine or contaminating the sample.

What the Test Results Mean

Urine magnesium levels can vary based on hydration, diet, and overall health. High levels might suggest kidney problems or excessive magnesium intake, while low levels could indicate dehydration or other metabolic issues. Your results will be compared to reference ranges specific to your lab and health profile.

Common Conditions Monitored

This test is often used to evaluate kidney function, particularly in conditions like chronic kidney disease, nephrotic syndrome, or hypermagnesaemia (high magnesium levels). It can also help diagnose or monitor conditions affecting mineral metabolism, such as hypomagnesaemia (low magnesium) or certain genetic disorders.

Reference range

Adult: 1.7-2.2 mg/dLN/A

Specimen: urine

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Urine Magnesium

Frequently asked questions

What factors might affect my urine magnesium test results?
Several factors can influence your urine magnesium levels, including hydration status, dietary intake of magnesium-rich foods (like nuts, leafy greens, or dairy), certain medications, and underlying health conditions like kidney disease or diabetes. Always discuss any medications or supplements you’re taking with your provider before the test.
How often should I get this test?
The frequency of this test depends on your health condition and why it was ordered. Some people may need it yearly or more often if they have chronic kidney disease, metabolic disorders, or other ongoing health concerns. Follow your healthcare provider’s recommendations for timing and repeat testing.
Can I drink water during the 24-hour urine collection period?
Yes, you should drink plenty of water to ensure adequate urine production, but avoid excessive intake that could dilute the sample unnecessarily. Stick to your usual fluid intake unless instructed otherwise by your provider.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy