Division of Nephrology

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Electrolyte Disorders
 


Corresponding Experts


Aaron Dall, MD
Samuel S. Blumenthal, MD
Kevin Regner, MD
Barbara A. Bresnahan, MD
Jack Kleinman, MD
Eric Cohen, MD
 

Hyperkalemia:
The most common cause of high potassium (hyperkalemia) is impaired kidney function. Other causes of hyperkalemia include:

  • Certain medications, such as angiotensin-converting enzyme (ACE) inhibitors, Angiotensin Receptor Blocker (ARB) Heparin, Bactrim.
  • Hormone deficiencies, including adrenal failure (Addison's disease)
  • Destruction of red blood cells due to severe injury or burns
  • Excessive use of potassium supplements

Most of the potassium in your body is within your cells. As a result, the amount of potassium in your red blood cells is much greater than in the liquid part of your blood (plasma or serum). Your kidneys control the excretion of potassium in your urine.
True hyperkalemia is a serious and potentially life-threatening disorder. It can cause:

  • Muscle fatigue
  • Weakness
  • Paralysis
  • Abnormal heart rhythms (arrhythmias)

Sometimes a report of high blood potassium isn't true hyperkalemia. Instead it may be caused by the rupture of red blood cells in the blood sample during or shortly after drawing the sample. The ruptured cells leak their potassium into the serum. This falsely elevates the amount of potassium in the blood sample, even though the potassium level in your body is actually normal.
Hypokalemia:
Low potassium in the blood (hypokalemia) may result from many different conditions. The most common cause is excessive potassium loss in the urine or from the gastrointestinal tract, such as due to:

  • Use of diuretics
  • Excessive production of the hormone aldosterone (hyperaldosteronism) by the adrenal gland
  • Excessive use of laxatives
  • Eating disorders
  • Severe vomiting or diarrhea

Rarely, hypokalemia is due to not getting enough potassium in your diet.
Potassium is an electrolyte that is critical to the function of nerve and muscles cells, including those in your heart. Most of the potassium in your body is inside your cells. So the levels of potassium in your blood may not reflect your total body potassium.
Signs and symptoms of low potassium may include:

  • Weakness
  • Fatigue
  • Muscle cramps
  • Constipation
  • Abnormal heart rhythms (arrhythmias)
  • Certain kidney diseases such as renal tubular acidosis

Treatment is directed at the underlying cause of the low potassium and may include potassium supplements. A very low potassium level is life-threatening.

Hypercalcemia:
Hypercalcemia is a higher than normal level of calcium in the blood. The most common cause is an overactive parathyroid gland (hyperparathyroidism). The parathyroid glands, which are located below the thyroid gland, regulate calcium in your body.
Other causes of hypercalcemia include:

  • Certain medications, such as lithium or thiazide diuretics
  • Certain cancers, including breast, lung and certain blood cancers
  • Sarcoidosis, an inflammatory disorder
  • Excessive intake of calcium or vitamin D supplements
  • Familial hypocalciuric hypercalcemia, a genetic disorder
  • Dialysis for chronic kidney failure
  • Adrenal gland failure
  • Overactive thyroid (hyperthyroidism)

Severe hypercalcemia may cause:

  • Nausea, vomiting
  • Excessive thirst
  • Constipation
  • Abdominal pain
  • Muscle weakness
  • Confusion
  • Lethargy and fatigue

A doctor may make a diagnosis of hypercalcemia by a blood test. Treatment is directed at the underlying cause. Severe hypercalcemia may require hospitalization to reduce calcium to safe levels. In such cases, treatment may include:

  • Intravenous fluids
  • Diuretics
  • Bisphosphonates
  • Glucocorticoids (corticosteroids)

If untreated, hypercalcemia can lead to:

  • Kidney stones
  • Osteoporosis
  • Abnormal heart rhythm (arrhythmia)
  • Kidney failure

 

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Page Updated 03/21/2014