Potassium is an electrolyte that allows your nerves and muscles to work—including your heart. It is the most plentiful ion inside your cells. Healthy kidneys control blood potassium levels. Having the right level is vital, because just a little too much or too little can cause sudden death.

Potassium is found in many fruits and vegetables, like oranges and bananas. When the kidneys fail, careful meal planning can help you keep safe potassium levels. You can learn more about meal planning in Module 9—Nutrition and Fluids for People on Dialysis.

Too much potassium in your blood, hyperkalemia, can make your muscles very weak and stop your heart. Too little potassium, hypokalemia, can cause fatigue, muscle weakness, paralysis, and abnormal heart rhythms.