High potassium (hyperkalemia): causes, risks and what to eat

Dr. Joan J. Morales Lappot, MD
3 min read · Leer en español

In briefPotassium is essential for your heart and muscles, but the right amount lives in a narrow range. When kidneys cannot remove the extra, levels can rise quietly.

Why it rises

• Reduced kidney function
• Some blood pressure and heart medicines, such as ACE inhibitors, ARBs and spironolactone
• Potassium-based salt substitutes
• Uncontrolled diabetes
• Dehydration or a sudden kidney injury
• A falsely high reading if the blood sample is damaged during the draw

Why it matters

Very high potassium can disturb the heart's rhythm. Most people feel nothing until levels are dangerous; some notice weakness, numbness or palpitations. That is why blood tests matter when you have kidney disease or take these medicines.

How it is managed

• Reviewing medicines, including over-the-counter salt substitutes and supplements
• Adjusting diet only if your levels are high
• Medicines called potassium binders, which help remove potassium through the gut
• Treating constipation, which lets potassium build up
• Keeping helpful heart and kidney medicines when possible, with closer monitoring

Food, without fear

If your potassium runs high, smaller portions of high-potassium foods (bananas, oranges, potatoes, tomatoes, avocado, beans, plantains) help. Peeling, cutting and boiling potatoes in plenty of water removes some potassium. But if your level is normal, these foods are healthy, and cutting them out can do more harm than good.