You can have a high blood potassium level (hyperkalemia) for several reasons. Kidney disease is one of the most common causes. And medicine that makes the kidneys hold on to potassium can also cause it, including:

• Certain diuretics such as spironolactone (Aldactone, generic) and triamterene (Dyrenium, generic)
• Angiotensin converting enzyme inhibitors (ACE inhibitors)
• Angiotensin-receptor blockers (ARBs)
• Nonsteroidal anti-inflammatory drugs such as ibuprofen or naproxen

Two other causes of high potassium include:

• Using a salt substitute that has potassium in it
• Or taking a potassium supplement

Instead of looking for foods low in potassium, it might be easier for your friend to avoid foods that are high in potassium.

Here are some foods with the highest potassium content:

• Potatoes with skins
• Halibut
• Raisins
• Bananas
• Acorn squash
• Spinach
• Tomatoes and tomato sauce