Hypermagnesemia

Hypermagnesemia is a rare condition where you have too much magnesium, an electrolyte, in your blood. Typically, you don’t have much magnesium (Mg) in your blood. Your body keeps most of the magnesium it absorbs and stores it in your muscles and bones. Everyone needs magnesium for a variety of functions, from using energy and repairing DNA to forming bones.

Your kidneys filter most of the magnesium in your blood. A small amount of this mineral comes out in your urine (pee). When your kidneys work well, they can clear out a lot of magnesium. But people who have kidney failure and take medicines that contain magnesium can end up with this electrolyte disorder.

Because it’s not routine for healthcare providers to check magnesium levels, this disorder can be tricky to catch. Also, early symptoms can look like those of other conditions. But early diagnosis and treatment are best. Without prompt care, severe hypermagnesemia can be fatal.

Mild cases of Mg toxicity (high magnesium) typically don’t need treatment.

Symptoms of hypermagnesemia

People with a mild case of this condition might not have symptoms. Low blood pressure (hypotension) that doesn’t respond to medicine may be one of the first symptoms. With a moderate or severe case, hypermagnesemia symptoms may include:

• Dizziness
• Nausea
• Confusion
• Weakness
• Difficulty breathing

Hypermagnesemia causes

Kidney failure is the most common cause of hypermagnesemia. Other causes include:

• Addison’s disease
• Adrenal insufficiency (not producing enough cortisol)
• Hemolysis (red blood cell destruction)
• Hypercalcemia (high calcium levels)
• Hypothyroidism (underactive thyroid)
• Inflammatory bowel disease
• Injury from trauma, shock or burns
• Lithium-based psychotropic drugs
• Long-term use of antacids or laxatives with magnesium in them
• Use of enemas with magnesium in them
• Use of over-the-counter products with a lot of magnesium, like Epsom salts
• Treatment for eclampsia during pregnancy

Risk factors

The main risk factors for high magnesium are having acute or chronic kidney disease and ingesting products that contain magnesium.

Complications of this condition

Signs of more severe magnesium toxicity (when your magnesium is too high) may include:

• Drowsiness
• Headache
• Constipation
• Paralyzed muscles or bladder
• Coma
• Arrhythmia (abnormal heart rhythms) leading to cardiac arrest

How doctors diagnose hypermagnesemia

Healthcare providers use blood tests to check for this condition. A high magnesium level is above 2.6 milligrams per deciliter (mg/dL). A normal magnesium level is 1.7 to 2.3 mg/dL.

Levels of hypermagnesemia are:

• Mild (less than 7 mg/dL)
• Moderate (7 to 12 mg/dL)
• Severe (more than 12 mg/dL)

Your provider may also order a blood test and urinalysis to check your kidney function and an electrocardiogram (EKG) to check for abnormal heart rhythms.

How is it treated?

If your kidneys work well and you don’t have symptoms, you probably don’t need treatment. You’ll just need to stop taking medicines that have magnesium in them. Talk to your healthcare provider about other medications you can take instead.

Providers treat hypermagnesemia with IV fluids and IV medicines like diuretics and calcium gluconate. Diuretics like furosemide help your kidneys get rid of magnesium. Calcium gluconate can help with your breathing. You may also need dialysis to help quickly remove magnesium from your body.

If your heart and lungs need support, you may receive care in an intensive care unit.

When should I see my healthcare provider?

Contact a provider if you’re having symptoms of hypermagnesemia. Be sure to tell them about any over-the-counter supplements or medicines you use.

You may want to ask your provider:

• Am I at risk for a magnesium overdose?
• Do I need treatment?
• What should I use in the future instead of antacids or laxatives that contain magnesium?
• Can I still eat foods that contain a lot of magnesium?

Can this be prevented?

Yes, pharmacists and other providers can help you prevent hypermagnesemia. They can make sure that the medicines you’re taking don’t put you at risk for this condition. Knowing the signs of magnesium toxicity can help you alert a provider as soon as you start to have symptoms.

What can I expect if I have hypermagnesemia?

The prognosis for this condition depends on the severity of your case. Mild hypermagnesemia is often a harmless condition. But a severe case can be fatal.

What foods should I avoid with hypermagnesemia?

Many foods are rich in magnesium. Examples include:

• Bananas
• Black beans
• Broccoli
• Brown rice
• Green vegetables
• Meat and seafood
• Nuts like almonds and cashews
• Seeds
• Whole grains

Talk to your provider about which foods are safe for you and which ones you should avoid.