What is hypomagnesemia?
Hypomagnesemia, also known as magnesium deficiency, happens when you have a lower-than-normal level of magnesium in your blood. It can be mild or severe.
Magnesium is an electrolyte that’s a key part of many bodily reactions that affect cellular function, nerve conduction and more. Your brain, heart and muscles rely heavily on magnesium to do their job.
Magnesium has a direct effect on the balance of other electrolytes, including sodium, calcium and potassium. Hypomagnesemia often happens alongside hypocalcemia (low blood calcium levels) and hypokalemia (low blood potassium levels).
It should be noted that while most of your body’s magnesium is stored in your bones, it’s only the magnesium dissolved in extracellular fluid (mostly blood plasma) that’s available for use by cells and organs.
Three organs are responsible for maintaining normal magnesium levels, including your:
- Small and large intestines, which absorb magnesium from the food you eat.
- Bones, which are the main storage system for magnesium.
- Kidneys, which are responsible for the excretion (release) of magnesium through your pee.
If there’s an issue in any step of this process, it can cause hypomagnesemia.
Who does hypomagnesemia affect?
Hypomagnesemia can affect anyone at any age. People with certain health conditions and in certain situations are more likely to have hypomagnesemia. It occurs in:
Symptoms and Causes
What are the symptoms of hypomagnesemia?
Hypomagnesemia can present in many different ways, but it mainly affects your neuromuscular system and heart. Some people don’t have any symptoms (are asymptomatic).
Symptoms of mild hypomagnesemia include:
- Tetany (muscle spasms, muscle cramps and/or numbness in your hands and feet).
- Abnormal eye movements (nystagmus).
- Fatigue and weakness.
Symptoms of severe hypomagnesemia include
It’s important to seek medical care if you’re experiencing these symptoms.
What causes hypomagnesemia?
Hypomagnesemia usually happens due to one of the following:
- Too little intake of magnesium into your body.
- Excessive loss of magnesium through your kidneys (pee) or your gastrointestinal tract (stool).
- Movement of magnesium from extracellular fluid into less accessible locations (less common).
Too little intake of magnesium
Nutritional deficiencies due to poor intake of magnesium include:
- Alcohol use disorder with poor nutritional intake.
- Critically ill people who cannot take food by mouth and must receive all their nutrients by IV.
Deficiencies due to poor absorption of magnesium from the gastrointestinal tract include:
- Diseases causing malabsorption such as celiac disease and inflammatory bowel disease.
- Gastric bypass surgery.
- Hereditary syndromes causing poor absorption of magnesium (primary intestinal hypomagnesemia).
- Medications which can cause interference with magnesium absorption (proton pump inhibitors such as omeprazole).
Excessive loss of magnesium
Excessive losses of magnesium from the kidneys (pee) include:
- Alcohol use disorder.
- Uncontrolled diabetes.
- Inherited kidney tubular disorders, such as Gitelman syndrome.
- Diuretic drugs (hydrochlorothiazide, chlorthalidone, furosemide, bumetanide).
- Aminoglycoside antibiotics (gentamicin, tobramycin, amikacin, plazomicin, streptomycin, neomycin, paromomycin).
- Chemotherapy drugs (cisplatin).
- Anti-rejection drugs (cyclosporine, tacrolimus).
- Other drugs (digoxin).
Excessive losses of magnesium through the gastrointestinal tract (poop):
- Acute or chronic diarrhea.
Movement of magnesium from extracellular fluid to less accessible locations
This can happen in people with:
- Acute pancreatitis.
- “Hungry bone disorder” a condition that can develop following the surgical removal of parathyroid glands.
Diagnosis and Tests
How is hypomagnesemia diagnosed?
If you’re experiencing symptoms of hypomagnesemia, your healthcare provider will perform a physical exam and ask about your symptoms and medical history.
They’ll likely order a blood test to check your magnesium level. Normal magnesium levels are usually between 1.46 and 2.68 milligrams per deciliter (mg/dL).
They may also order the following tests:
- Calcium blood test.
- Comprehensive metabolic panel.
- Potassium blood test.
- Urine magnesium test.
- Electrocardiogram (EKG).
Once your provider confirms you have hypomagnesemia, they can usually determine the underlying cause based on your medical history and test results. If they’re unsure, they may need to run more tests to help diagnose the cause.
Management and Treatment
How is hypomagnesemia treated?
Treatment for hypomagnesemia depends on how mild or severe it is and the underlying cause.
If the hypomagnesemia is mild, your healthcare provider will likely recommend magnesium tablets taken by mouth.
If the hypomagnesemia is severe, you’ll likely be in a hospital and receive fluids and magnesium through an IV.
Your provider will also prescribe a treatment plan to manage the underlying cause.
Can I prevent hypomagnesemia?
Treating and/or managing underlying conditions that can cause hypomagnesemia can help prevent episodes.
For example, if you have celiac disease, maintaining a strict gluten-free diet can prevent malabsorption (which could cause hypomagnesemia).
However, in some cases, you can’t prevent hypomagnesemia.
Outlook / Prognosis
What is the prognosis (outlook) for hypomagnesemia?
The prognosis (outlook) for hypomagnesemia depends on its underlying cause. People who have hypomagnesemia from an identifiable cause have a good prognosis for complete recovery if they receive treatment.
Dangerously low levels of magnesium have the potential to cause fatal cardiac arrhythmias.
When should I see my healthcare provider about hypomagnesemia?
If you’re experiencing symptoms of hypomagnesemia, you should see your healthcare provider. If you have severe symptoms, such as seizures or an abnormal heartbeat, call 911 or get to the nearest hospital as soon as possible.
If you have a chronic condition that can lead to hypomagnesemia, such as Crohn’s disease or an inherited kidney (renal) tubular disorder, it’s important to see your healthcare team regularly to make sure your treatment is working and your magnesium levels are in a healthy range.
A note from Cleveland Clinic
Getting a diagnosis can be stressful. Know that hypomagnesemia is treatable and that symptoms usually go away once your magnesium levels are back to normal with treatment. Don’t be afraid to ask your healthcare provider questions about hypomagnesemia and its management.
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