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Hypermagnesemia (High Level of Magnesium in the Blood)


James L. Lewis III

, MD, Brookwood Baptist Health and Saint Vincent’s Ascension Health, Birmingham

Last full review/revision Apr 2020| Content last modified Apr 2020

In hypermagnesemia, the level of magnesium in blood is too high.

(See also Overview of Electrolytes and Overview of Magnesium's Role in the Body.)

Magnesium is one of the body's electrolytes, which are minerals that carry an electric charge when dissolved in body fluids such as blood, but the majority of magnesium in the body is uncharged and bound to proteins or stored in bone. Bone contains most of the magnesium in the body. Very little magnesium circulates in the blood.

Hypermagnesemia is uncommon. It usually develops only when people with kidney failure are given magnesium (Epsom) salts or take drugs that contain magnesium (such as some antacids or laxatives).

Hypermagnesemia may cause

  • Muscle weakness
  • Low blood pressure
  • Impaired breathing

When hypermagnesemia is severe, the heart can stop beating.

The diagnosis is based on blood tests indicating that the magnesium level is high.

Treatment of Hypermagnesemia

  • Calcium gluconate
  • Diuretics

People with severe hypermagnesemia are given calcium gluconate by vein (intravenously).

Diuretics (particularly if given intravenously) can be given to increase the kidneys’ excretion of magnesium. However, if the kidneys are not functioning well or if hypermagnesemia is severe, dialysis is usually needed.

Drugs Mentioned In This Article

Generic Name Select Brand Names
Calcium gluconate No US brand name

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