What is hyperkalemia (high blood potassium levels)?

Hyperkalemia happens when potassium levels in a person’s blood are higher than normal.

Normal levels of potassium in the blood are generally between 3.7 and 5.2 mEq/L (milliequivalents per liter) for adults and 3.4-4.7 mEq/L for children. For adults, the safety range for potassium levels is usually between 3.5 and 5.5 mEq/L.

If potassium levels drop below 3.5 or go over 6, that person is no longer within the safety range for potassium blood levels and should speak with a doctor.

Potassium normally helps to:

  • Regulate muscle tissue
  • Metabolize
  • Maintain the balance between electrical and chemical processes in the body

Who can get hyperkalemia?

Anyone can get hyperkalemia, but there are some groups who are more at risk. People who have kidney disorders, infants, elderly patients in hospitals, and those who abuse drugs have an increased risk of high potassium levels.

What are the symptoms of hyperkalemia (high blood potassium levels)?

A person with high levels of blood potassium may not have any symptoms. However, if symptoms do exist, they may include:

  • Muscle weakness
  • Irregular heartbeat
  • Slow, weak, or absent pulse

What causes high blood potassium levels?

Hyperkalemia can have a variety of causes:

  • Increased total body potassium
  • Cells releasing extra potassium into the bloodstream
  • Lack of aldosterone, the hormone that helps the kidneys to regulate potassium levels
  • Some medicines, including potassium supplements, can cause hyperkalemia

The possible problems that have been found in people with hyperkalemia are:

  • Irregular heartbeat
  • Cardiac arrest (heart attack)
  • Changes in nerve and muscle control

Last reviewed by a Cleveland Clinic medical professional on 10/19/2016.


  • American Academy of Family Physicians. Hyperkalemia Accessed 1/9/2017.
  • National Kidney Foundation. Potassium and Your CKD Diet Accessed 1/9/2017.
  • Hirsch S. An update on proteinuric chronic kidney disease: the dual-goal approach. Cleve Clin J Med. 2008; 75:705–713.

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