Information about a laboratory test

Low Magnesium: What Does It Mean?

A low result can occur with kidney, hormonal, nutritional, absorption or medication-related factors; related minerals and clinical context matter.

Test summary

Test name
Magnesium
Abbreviations
Mg
Category
Minerals / Electrolytes
Panel
Bone & Mineral Metabolism
Specimen
Serum / plasma
Common units
mg/dL, mmol/L

What does the test measure?

The Magnesium test measures blood magnesium related to muscle, nerve, cardiac and bone function.

Why is the test ordered?

Ordered with related tests to assess mineral balance, kidney/endocrine regulation or bone metabolism.

Information about a low result

A low result can occur with kidney, hormonal, nutritional, absorption or medication-related factors; related minerals and clinical context matter.

Information about a high result

A high result can occur with kidney, hormonal, supplement/medicine or other mineral-balance factors; related tests provide context.

Reference and clinical context

Start with the performing laboratory's reference interval, unit, specimen type and method. Numeric information on this page is stored as sourced example intervals or clinical thresholds.

Reference range 1

>= 1.6 – <= 2.6 mg/dL

Population
Adults
Age range
18
Specimen
Serum

Sourced example reference interval for Magnesium

This is a sourced example reference interval; laboratory, method, age and clinical context can change the range. The user's own report takes priority.

Reference ranges may vary by laboratory, method used, age, sex, pregnancy status, and clinical context. The reference range on your own laboratory report takes precedence.

Interpretation notes

A single mineral value is often insufficient; PTH, vitamin D, kidney function and related minerals may need to be interpreted together.

Related specialties

  • Endocrinology
  • Internal Medicine
  • Nephrology
  • Family Medicine

Frequently asked questions

Sources

  1. Calcium Blood Test — U.S. National Library of Medicine (MedlinePlus)

    Government medical reference · 2025 · Total calcium purpose, albumin context and example adult reference interval · Verified: Aug 12, 2026

  2. Magnesium Blood Test — U.S. National Library of Medicine (MedlinePlus)

    Government medical reference · 2023 · Magnesium testing, kidney/intestinal regulation and related minerals · Verified: Aug 12, 2026

  3. Magnesium Deficiency — U.S. National Library of Medicine (MedlinePlus)

    Government medical reference · 2025 · Example serum magnesium reference interval and lab-variation caveat · Verified: Aug 12, 2026

  4. Phosphate in Blood — U.S. National Library of Medicine (MedlinePlus)

    Government medical reference · 2023 · Phosphate interpretation with calcium, PTH, vitamin D and kidney function · Verified: Aug 12, 2026

  5. Parathyroid Hormone (PTH) Blood Test — U.S. National Library of Medicine (MedlinePlus)

    Government medical reference · 2025 · Example PTH interval and calcium-dependent interpretation · Verified: Aug 12, 2026