Hypomagnesemia
Definition
Hypomagnesemia means low levels of magnesium in the blood.
Alternative Names
Low blood magnesium; Magnesium - low
Causes
Several conditions can cause hypomagnesemia, including:
- Alcoholism
- Chronic diarrhea
- High blood calcium levels (hypercalcemia)
- Hyperaldosteronism
- Malabsorption syndromes, such as celiac disease and inflammatory bowel disease
- Malnutrition
- Medications including amphotericin, cisplatin, cyclosporine, diuretics, and aminoglycoside antibiotics
- Excessive urination (polyuria), such as in uncontrolled diabetes and during recovery from acute kidney failure
- Sweating
Symptoms
Common symptoms include:
- Abnormal eye movements (nystagmus)
- Convulsions
- Fatigue
- Muscle spasms or cramps
- Muscle weakness
- Numbness
Exams and Tests
Your health care provider will do a complete physical examination to help determine the cause of your symptoms.
Signs include:
- Electrocardiogram (ECG) changes
- Low blood calcium level (hypocalcemia)
- Low blood potassium level (hypokalemia)
Blood and urine tests will be done. Other tests that can confirm hypomagnesemia include:
- Comprehensive metabolic panel
- Magnesium blood test
- Urine magnesium test
Treatment
The cause of hypomagnesemia must be diagnosed and treated. Treatment depends on the type of hypomagnesemia, but may include:
- Fluids given through a vein (IV)
- Magnesium by mouth or through a vein
- Medication to relieve symptoms
Outlook (Prognosis)
The outcome depends on the condition that is causing the problem.
Possible Complications
- Cardiac arrest
- Death
- Respiratory arrest
When to Contact a Medical Professional
Hypomagnesemia can be a life-threatening emergency. Call your health care provider if you have symptoms of this condition.
Prevention
Treating the condition that is causing hypomagnesemia can help. If you play any demanding sports, drink fluids that contain electrolytes (sports drinks). Drinking only water while you take part in high-energy athletic events can lead to acute hypomagnesemia.
References
Pollak MR, Yu ASL, Taylor EN. Disorders of calcium, magnesium, and phosphorous balance. In: Brenner BM, ed. Brenner and Rector's The Kidney. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2008:chap 16.
Yu ASL. Disorders of magnesium and phosphorous. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 120.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

