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A Suprising Cause of High Potassium in Kidney Disease - And 5 Low Potassium Foods to Resolve It

Updated: Apr 24

Potassium is unfairly treated in the kidney community. When I was a hospital dietitian, before I specialized in kidney disease, we would absolutely terrify new kidney patients with “No potassium ever or you’ll have a heart attack” diet education with little explanation.

The kidneys get rid of potassium at a slower rate as kidney disease worsens, so it's important for us to monitor potassium in the blood. If it gets too high, it can cause heart palpitations and cardiac arrest which are obviously very scary problems. But, we don't really talk about how to address it other than to give you a list of high potassium "no-no" foods.

Now that I’m a renal dietitian and Certified Specialist in Renal Nutrition, I can offer you a little more insight on what causes high potassium in kidney disease than I could have before so that you understand a bit more about your kidney disease.

Things That Lead to High Potassium in Kidney Disease:

  • Certain medications

  • Some dietary supplements (like Ensure or Boost)

  • Regularly eating foods high in potassium (bananas, orange juice, potatoes, etc)

  • Skipping dialysis treatments - Do not do this!

  • Uncontrolled blood sugar

  • Acidosis - when the blood becomes too acidic

But, do you know what the most surprising cause of high potassium has been in my practice?

Chronic constipation.

Sometimes it’s a medication or dehydration that drives potassium up. But, sometimes it’s because they're backed up.

Kidneys, Potassium, and Poop

Our kidneys get rid of most of our extra potassium in our urine (about 90-95% in healthy kidneys). When the kidneys begin to work less effectively, the large intestine can actually pick up some of the slack(1) and excrete extra potassium into the stool. So, we see more potassium excreted into the stool in CKD. But, when we aren't having regular bowel movements, we can reabsorb that potassium waste which is not good. We want to get rid of the potassium, not just keep reabsorbing it constantly.

A woman clutches her stomach in pain
Chronic constipation isn't just a normal part of aging. It can have a big impact on your kidney and heart health.
How do I know if I’m constipated?

Constipation is(1):

  • Having 3 or fewer stools per week

  • Straining or having difficulty passing stool

  • Passing hard, lumpy, or painful stools

Chronic constipation is incredibly common in kidney disease affecting up to 70% of people with CKD and up to 90% of people with End-Stage Renal Disease (ESRD) - these people are typically on dialysis(2).

Simple Solutions for Constipation in CKD

Talk to your doctor

You should be pooping regularly and it shouldn’t hurt. Your provider can recommend affordable over the counter options and can order you a prescription if necessary.

Eat more fiber

Fruits, vegetables, beans, nuts, peas, and grains are all great sources of fiber. You know how your grandma always said that greens keep her bowels moving? That’s the fiber. It can increase bulk, retain fluid, and actually help the bowels to secrete more fluid to keep you regular.

Drink more water 

The body pulls more fluid from chyme if you’re dehydrated. So, drink up! Unless your doctor has you on a fluid restriction. Then stick to the doctor's orders.

Move your body

A Scandinavian study found that 30 minutes of brisk walking and just 11 minutes of a home based workout program a day led to a decrease in overall constipation(3). You can literally work it out. 

Does this mean that I still have to avoid high potassium foods?

Yes. If your doctor told you to avoid them, then avoid them. If the potassium in your blood is already high enough to concern your doctor, you need to limit high potassium foods while your potassium comes back down to a normal level.

But, it does mean that you may not always have to limit these foods.

What I want is for you to stop thinking that it’s normal to poop every other day. It’s not. It’s not normal to strain. It’s not normal for it to hurt. I want you to talk to your doctor about how you're pooping! 

I want you and your doctor to rule out this incredibly common issue before cutting all of your favorite foods out of your diet forever.

If you want to start working your favorite higher potassium foods back into your diet, wait until your doctor has looked at your new lab work and has given you the ok to do so!

In the meantime, I’m going to leave you with a list of my top favorite low potassium foods to help get your bowels moving to hopefully bring that potassium down.

My 5 Favorite Low Potassium Foods to Fight Constipation

  • Green peas - ½ cup has about 4 grams of fiber

  • Oatmeal - 1 cup cooked has about 5g of fiber

  • Pecans - 1 oz has about 3g of fiber

  • Chickpeas - ½ cup has about 5 grams of fiber

  • Blackberries - 1 cup has about 8 grams of fiber

Now, should you start eating all of these tomorrow? No. You’ll probably get gassy and bloated.

If you’re trying to increase your fiber intake, I always recommend doing it one day at a time. Add some green peas to dinner tonight. Snack on some blackberries tomorrow. In a couple of days, try some oatmeal with pecans.  

Do you see where I’m going with this? Slowly, start incorporating these foods so that you don’t feel like you have a balloon sitting in your belly.


The big points from today’s post are:

  • Constipation is not normal. You need to talk to your doctor about it.

  • Constipation can cause high potassium. You and your doctor definitely want to address it, especially if there’s a chance that you could eat your favorite potassium-rich foods again.

  • There are lots of low potassium foods that can help to keep you regular.

  • You should ask your doctor for a referral to a renal dietitian if your diet is making you miserable. We can help!


Brandy Winfree, RDN smiling at the camera.

I'm Brandy Winfree, RDN.

When I was working in dialysis, I saw so many patients who had no idea that diet plays a HUGE role in kidney health.

I decided then that I needed to pass my knowledge onto people with kidney disease BEFORE they went into kidney failure. Not after.

That's why I became a board Certified Specialist in Renal Nutrition and why I started this blog. 

You deserve to take care of the kidneys that you have now and I want to share my knowledge with you to make that happen.

Are they any topics that you'd like to hear my thoughts on?

Shoot me a message here.

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