Hypophosphatemia (Low Level of Phosphate in the Blood)

Acute hypophosphatemia

In acute hypophosphatemia, the phosphate level in blood suddenly falls dangerously low. Because the body uses large amounts of phosphate during recovery from certain disorders, acute hypophosphatemia may occur in people recovering from the following conditions:

• Severe undernutrition (including starvation)
• Diabetic ketoacidosis
• Severe alcoholism
• Severe burns

This sudden drop in phosphate level may result in an abnormal heart rhythm and even death.

Chronic hypophosphatemia

In chronic hypophosphatemia, the phosphate level in blood becomes low over time. Chronic hypophosphatemia usually develops because too much phosphate is excreted. Causes include the following:

• Hyperparathyroidism
• Chronic diarrhea
• Use of diuretics for a long time
• Use of large amounts of aluminum-containing antacids for a long time
• Use of large amounts of theophylline (used to treat asthma)

Symptoms

Symptoms of hypophosphatemia occur only when the phosphate level in blood becomes very low. Muscle weakness develops, followed by stupor, coma, and death.

In mild chronic hypophosphatemia, the bones can weaken, resulting in bone pain and fractures. People may become weak and lose their appetite.

Diagnosis

• Measurement of phosphate levels in the blood

Hypophosphatemia is diagnosed when blood tests show that the level of phosphate in the blood is low. Doctors do other tests to identify the cause if it is not readily apparent.

Treatment

• Increase phosphate intake

Drugs that reduce the phosphate level are stopped.

If hypophosphatemia is mild and causes no symptoms, drinking low-fat or skim milk, which provides a large amount of phosphate, may help. Or people can take phosphate by mouth, but doing so usually causes diarrhea.

If hypophosphatemia is very severe or if phosphate cannot be taken by mouth, phosphate may be given by vein (intravenously).

Drugs Mentioned In This Article