What is hyperkalemia (high potassium)?

Hyperkalemia occurs when potassium levels in your blood get too high. Potassium is an essential nutrient found in foods. This nutrient helps your nerves and muscles function. But too much potassium in your blood can damage your heart and cause a heart attack. You can’t always tell when your potassium levels are high.

What is a safe or normal potassium level?

A typical potassium level for an adult falls between 3.5 and 5.0 millimoles per liter (mmol/L). Hyperkalemia occurs when levels go above 5.5 mmol/L. A reading above 6.5 mmol/L can cause heart problems that require immediate medical attention.

Who might have hyperkalemia (high potassium)?

Anyone can get hyperkalemia, even children. You may be more at risk if you have:

What causes hyperkalemia (high potassium)?

Your kidneys filter potassium from the foods and drinks you consume. Your body gets rid of excess potassium when you pee. With hyperkalemia, your body has too much potassium for your kidneys to remove. As a result, potassium builds up in your blood.

In addition to conditions like kidney disease, these factors also contribute to hyperkalemia:

  • A high-potassium diet, which can result from potassium supplements and salt substitutes.
  • Medications that contain potassium, such as certain high blood pressure medicines.

What are the symptoms of hyperkalemia (high potassium)?

Many people with mild hyperkalemia have no signs or ones that are easy to dismiss. Symptoms often come and go and may come on gradually over weeks or months. Dangerously high potassium levels affect the heart and cause a sudden onset of life-threatening problems. Hyperkalemia symptoms include:

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