What are the symptoms of hypermagnesemia (elevated magnesium levels)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: March 30, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Hypermagnesemia is a life-threatening condition that can cause severe neurological and cardiovascular symptoms, including muscular weakness, paralysis, ataxia, drowsiness, confusion, vasodilation, hypotension, bradycardia, cardiac arrhythmias, hypoventilation, and cardiorespiratory arrest, when serum magnesium levels exceed 2.2 mEq/L. According to the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1, hypermagnesemia can produce a range of symptoms due to its effects on the nervous and cardiovascular systems.

Key Symptoms

  • Muscular weakness
  • Paralysis
  • Ataxia
  • Drowsiness
  • Confusion
  • Vasodilation
  • Hypotension
  • Bradycardia
  • Cardiac arrhythmias
  • Hypoventilation
  • Cardiorespiratory arrest As noted in the study 1, extremely high serum magnesium levels can lead to depressed levels of consciousness, bradycardia, and cardiac arrhythmias, emphasizing the need for prompt recognition and treatment of hypermagnesemia to prevent severe morbidity and mortality.

From the Research

Hypermagnesemia Symptoms

The symptoms of hypermagnesemia can be severe and potentially life-threatening. Some of the symptoms include:

  • Neuromuscular dysfunction
  • Respiratory and cardiovascular negative outcomes
  • Coma 2
  • Dysautonomia
  • Muscle weakness
  • Respiratory failure
  • Altered level of consciousness from drowsiness to coma 3
  • Bradycardia
  • Hypotension
  • Altered mental status
  • Respiratory depression 4

Risk Factors

Certain populations are at a higher risk of developing hypermagnesemia, including:

  • Patients with impaired renal function 2, 5
  • Patients receiving magnesium-containing medications or supplements 2, 5
  • Patients with chronic kidney disease 5
  • Older hospitalized patients 6

Clinical Presentation

Hypermagnesemia can present with a range of symptoms, from mild to severe. In severe cases, it can lead to:

  • Respiring failure
  • Cardiac arrest
  • Coma 2, 4, 3
  • The symptoms can be nonspecific, making it important for healthcare providers to have a high level of suspicion for hypermagnesemia in at-risk patients 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Hypermagnesemia in Clinical Practice.

Medicina (Kaunas, Lithuania), 2023

Research

Daily magnesium intake and hypermagnesemia in hemodialysis patients with chronic kidney disease.

Journal of renal nutrition : the official journal of the Council on Renal Nutrition of the National Kidney Foundation, 2012

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.