Hypermagnesemia refers to a high magnesium level in the blood. It is uncommon and usually results from renal failure or kidney dysfunction. Symptoms include nausea, vomiting, neurological impairment, and more.

Magnesium is a mineral the body uses as an electrolyte, meaning it carries electric charges around the body when dissolved in the blood. It is involved in bone health, cardiovascular function, and neurotransmission, among other functions.

This article explores hypermagnesemia in more detail, including its causes, symptoms, diagnosis, and treatment. The article also discusses preventing hypermagnesemia and the potential outlook for people experiencing the condition.

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Hypermagnesemia is uncommon. It is the medical term for when too much magnesium circulates in the blood.

Typically, very little magnesium circulates in the blood. The gastrointestinal (gut) and renal (kidney) systems regulate how much magnesium the body absorbs from food and how much is excreted in urine.

The typical level of magnesium in the blood is around 1.7 to 2.4 milligrams per deciliter (mg/dL).

Doctors may diagnose hypermagnesemia if a person’s magnesium level is above 2.6 mg/dL. If magnesium levels exceed 4 mg/dL, a doctor may classify the hypermagnesemia as severe.

Most cases of hypermagnesemia occur in people with acute and chronic kidney disease. Hypermagnesemia occurs because the process that keeps magnesium in the body at typical levels does not work properly when people are experiencing these conditions.

When the kidneys do not work properly, they are unable to get rid of excess magnesium, and this makes the person more susceptible to a buildup of the mineral in the blood.

People taking high magnesium supplements, such as to manage eclampsia, and certain medications, such as lithium and magnesium-containing laxatives and antacids, may have an increased risk of hypermagnesemia.

Other causes of hypermagnesemia may include:

People may not always experience symptoms. However, the signs and symptoms of hypermagnesemia may include:

Severe high levels of magnesium in the blood can lead to:

Healthcare professionals first diagnose hypermagnesemia using a blood test. The level of magnesium found in the blood indicates the severity of the condition.

A typical magnesium level in the blood is between 1.7 and 2.4 mg/dL, and a level above 2.6 mg/dL defines hypermagnesemia.

A doctor may also recommend other diagnostic tools to identify signs and symptoms of severe hypermagnesemia. The tools may include:

The first step in treating hypermagnesemia is identifying and stopping the source of extra magnesium.

For severe hypermagnesia, healthcare professionals will then use an intravenous (IV) calcium or saline supply to reduce symptoms. They may also recommend diuretics and dialysis.

People with underlying kidney issues are at risk of developing hypermagnesemia because their kidneys may not be able to excrete enough magnesium.

Avoiding medications that contain magnesium can help prevent complications. This includes some over-the-counter antacids and laxatives. However, people should not stop taking any prescription medication without first consulting with their doctor.

Healthcare professionals may also monitor people with kidney problems for hypermagnesemia using blood tests.

Hypermagnesemia is usually treatable if a person receives an early diagnosis. If renal function is typical, the kidneys can excrete the excess magnesium quickly once a healthcare professional has identified and stopped the source of magnesium.

Severe hypermagnesemia can be harder to treat, particularly in individuals with damaged kidneys and especially if they do not receive a prompt diagnosis. Dialysis and IV therapy can stop symptoms quickly, however.

A 2015 study suggested that critically ill people who are already admitted to a hospital have a higher risk of death if they receive a hypermagnesemia diagnosis.

Hypermagnesemia is the medical term for a high level of magnesium in the blood. It typically results from acute and chronic kidney disease.

Symptoms can vary depending on the severity of the condition, they may include nausea, constipation, headaches, and dizziness. People with mild hypermagnesemia may not always experience symptoms.

Treatment typically involves a doctor identifying and stopping the source of extra magnesium. People with severe hypermagnesmia may require additional treatment, such as IV therapy.

Anyone who suspects they are experiencing hypermagnesmia should contact a healthcare professional.