Content updated on August 27, 2021 - Medically reviewed by our Medical Advisory Committee

What is high potassium, or hyperkalemia?

Everyone needs potassium to survive. Potassium is a mineral and an electrolyte. It helps your muscles work, including the muscles that control your heartbeat and breathing. Potassium comes from the food you eat.

Your body uses the potassium it needs. The extra potassium that your body does not need is removed from your blood by your kidneys. When you have kidney disease, your kidneys cannot remove extra potassium in the right way, and too much potassium can stay in your blood.

When you have too much potassium in your blood, it is called high potassium, or hyperkalemia. Having too much potassium in your blood can be dangerous. High potassium can even cause a heart attack or death! Unfortunately, many people do not feel symptoms of high potassium until it’s too late and their heart health worsens.

Manage your potassium levels with diet and treatment.

Frequently asked questions about hyperkalemia

What causes high potassium?

The most common cause of high potassium is kidney disease.

Other causes of high potassium include:

  • Dehydration
  • Some medicines
  • Uncontrolled diabetes
  • Injuries that cause severe bleeding
  • Some rare diseases

If you have kidney disease, you are at risk for high potassium because your kidneys cannot remove the extra potassium in your blood. Instead of leaving your body through your urine, the extra potassium in your blood travels through your kidneys and back into your bloodstream. Over time, more and more potassium can build up in your blood.

What are the symptoms of high potassium?

Many people do not feel symptoms of high potassium. Having too much potassium in your blood can be dangerous. It can even cause a heart attack.

If you do feel symptoms, some of the most common are:

  • Feeling tired or weak
  • Feeling sick to the stomach (nausea)
  • Muscle pains or cramps
  • Trouble breathing, unusual heartbeat, chest pains

If you have trouble breathing or think there could be a problem with your heart, call 911 for emergency help.

What are the complications of high potassium?

Having too much potassium in your blood can be dangerous. Potassium affects the way your heart’s muscles work. When you have too much potassium, your heart may beat irregularly, which in the worst cases, can cause heart attack.

If you think you are having a heart attack, call 911 for emergency help.

Some of the most common signs of heart attack are:

  • Feelings of pressure, pain, or squeezing in your chest or arms
  • Stomach pain or nausea
  • Shortness of breath
  • Breaking into a cold sweat
  • Sudden feelings of dizziness

What are the tests for high potassium?

The only way to know for sure if your potassium level is healthy is to have a blood test. The test measures how much potassium is in your blood.

The blood test is like many other blood tests that you may be familiar with. A small needle is placed into a vein on your arm and your blood is drawn out into a tube. The blood is sent to lab to be tested.

Potassium may be called something else in your test results. If you do not see ‘potassium’, look for either:

  • Serum potassium
  • K

A potassium of higher than 5.2 millimoles per liter (mmol/L) is usually considered high but your doctor or lab might use slightly different numbers. Talk to your doctor about what your test results mean.

Because very high potassium (higher than 6.0 mmol/L) can be dangerous, your doctor or nurse may contact you first if your results are unusually high. In this case, they may ask you to go to an emergency room or hospital.

What are the treatments for high potassium?

There are two ways to treat high potassium, through diet and/or medicine.

Potassium binders

Medicines for high potassium are called potassium binders. A potassium binder works by sticking to the potassium in your body and preventing some of it from being taken into your bloodstream. This helps to keep potassium from building up in your blood. The medicine is a powder, which you can take by mixing it with water and drinking. Talk to your doctor about whether a potassium binder could be an option for you.

Eating for high potassium

If you learn that you have high potassium, your doctor might suggest that you change your diet to take in less potassium.

Talk to your doctor or dietitian about how much potassium you should have and how you can control how much potassium you eat. Your dietitian can recommend foods that are low in potassium that you can eat instead of foods that are high in potassium.

Follow these tips to keep your potassium at the right level:

  • Avoid salt substitutes because they are usually high in potassium.
  • Do not forget about drinks. Many fruit juices, like orange and tomato, have high potassium. Potassium can also be found in other drinks including coconut water.
  • Pay attention to serving sizes. Use measuring cups and measuring spoons to make sure you know how many servings you are eating or drinking. Remember that if you eat two servings of a food with potassium, you are eating twice as much potassium!

To manage your potassium intake, you need to know how much potassium is in your food and drinks.

  • Packaged foods must have nutrition labels, but potassium is not always listed on the label. If you do not see potassium listed on the nutrition label, check the list of ingredients on the package. If the word potassium or an abbreviation for potassium (K, KCl or K+) is listed, there is potassium in the food.
  • Starting in July 2020, potassium values will be listed on food nutrition labels. You can read more about these changes here.
  • Fresh fruits, vegetables, meats, and some dairy products do not have nutrition labels. Ask your dietitian for a list of high-potassium foods and lower potassium options.

Plan ahead if you know you will be eating a meal that is high in potassium. For example, if you are going out for dinner and you know your meal will be higher in potassium, or you know that it will be hard to measure how much potassium is in your meal, plan to eat meals that are low in potassium for breakfast and lunch.

When eating out, choose a restaurant that will make changes or substitutions in their dishes. Bring a list of low potassium foods with you that the restaurant can substitute out for other items. Use this sample potassium log to start tracking how much potassium you eat at each meal.

Foods HIGH in potassium include:


Foods LOW in potassium include:

Some Fruits
Some Vegetables


If you are on dialysis or if you have a loved one who is, you know how difficult it can be to find foods that will work with the strict diet that dialysis requires. Watch our webinar and understand the differences between phosphorus and potassium and learn appropriate food sources of each.

How to talk to your doctor about high potassium

You might find it hard to manage high potassium on your own. The good news is that your health care team can help. Use these tips to start a conversation:

Be honest and do not be afraid to start the conversation. If you are having problems managing your high potassium, tell your healthcare team. Many people struggle with their diet and medicines. Your healthcare team will have lots of experience to help you come up with a plan.

Talk about any symptoms you are feeling. Muscle pains, feeling tired, and other symptoms could be caused by high potassium but there could be other causes.

Ask to see a dietitian. If you are a dialysis patient, you may already have a dietitian you can talk to. If you have kidney disease and are not yet on dialysis, many health insurance plans (including Medicare) will cover at least a few sessions with a dietitian.

Ask if there is a medicine that could help. Medicines called potassium binders might be able to help you if diet is not enough. Ask your healthcare team if potassium binders could be an option for you.