Potassium is a key mineral that supports muscle contraction, nerve function, and a steady heartbeat. It also helps balance fluid and electrolytes, which is crucial for maintaining healthy blood pressure.
The good news? Most people get enough potassium from their diet, without even needing to think about it. But for some, especially those with certain health conditions, too much potassium can be dangerous. Here’s what you need to know about getting the right amount, and when to be cautious.
How Much Potassium Is Too Much?
Most adults need around 2,500 to 3,400 mg of potassium per day, depending on age, sex, and activity level. If you eat a balanced diet full of fruits, vegetables, whole grains, dairy and protein-rich foods, you’re probably hitting your daily target without trying.
But regularly consuming more than 5,000 to 6,000 mg of potassium per day, especially if your kidneys have trouble filtering it, can lead to a buildup of potassium in the blood, increasing the risk of hyperkalemia (high potassium levels).
When does potassium become dangerous?
A normal blood potassium level is between 3.5 and 5.0 mmol/L.
Levels above 5.0 mmol/L are considered elevated and should be monitored.
Levels at or above 6.5 mmol/L can be life-threatening, as they may disrupt heart rhythm.
If your kidneys are healthy, your body will typically regulate excess potassium on its own.
What High Potassium Levels Mean
Elevated potassium can be tricky because it doesn’t cause noticeable symptoms at first. In fact, most people don’t know they have too much potassium in their blood until it shows up on a routine blood test. But when signs do show up, they can be anything from mild pain to more serious symptoms.
Signs your potassium may be high
If your potassium levels start to rise, you may notice:
Muscle weakness or fatigue
Irregular heartbeat
Numbness or tingling in the hands or feet
Nausea or vomiting
If you notice any of these symptoms, especially more than one at the same time, reach out to your health provider right away.
What causes elevated potassium?
Eating too many bananas is not usually the cause. High potassium levels typically happen when the body can’t get rid of potassium efficiently. Common reasons include:
Kidney disease. Problems with the kidneys can cause potassium to build up in the blood since the kidneys’ role is getting rid of extra potassium.
Certain medications, like ACE inhibitors and ARBs for high blood pressure, heart medicines, and potassium-sparing diuretics, can raise potassium levels.
Severe dehydration. Not drinking enough water can concentrate potassium levels in your blood and reduce kidney function.
Less commonly, conditions like adrenal insufficiency or uncontrolled diabetes can cause a raise in potassium levels in your blood. Also, if you suffer severe burns, a crush injury, or an infection, potassium can leak out of damaged cells and into your system.
If you are at risk of elevated potassium, you may need to carefully watch how much you eat and make changes to your diet.
How to Avoid Elevated Potassium
To keep potassium levels in check, you don’t have to completely avoid high-potassium foods. It’s more about making smart swaps and understanding your needs.
Pick foods low in potassium
If your doctor tells you to reduce potassium, opt for foods that are lower in potassium instead of foods that are higher in potassium.
Good swaps include:
Apples or berries instead of bananas
Pasta or rice instead of potatoes
Green beans or lettuce instead of spinach
Watch Out for Hidden Sources
Some multivitamins, protein powders, and salt substitutes contain added potassium. Be sure to check labels and talk to your provider or dietitian if you’re unsure.
Be Careful With Supplements
Many people take potassium supplements despite being able to easily get adequate levels from their diet. If your diet includes enough potassium, adding more can veer you into elevated levels that can be dangerous. Before taking potassium pills, you should always talk to a doctor, especially if you take medicine for your heart or blood pressure or have been advised by a doctor to limit potassium in your diet.
When to See A Doctor
Keep an eye out for signs like muscle weakness, heart palpitations, or feeling unusually tired. If you’re at risk for high potassium (due to kidney disease, medications, or chronic conditions), routine blood tests can help you stay ahead of problems. Make sure to stay on schedule with your regular check-ups!
The Bottom Line
Potassium is essential for good health, but balance is key. A Registered Dietitian can help you make sure you’re getting adequate nutrients, and can counsel you on how to lower any elevated levels—all in non-restrictive, sustainable ways. Book a session with a Culina Health RD to take the next step in your health journey!
Any general advice posted on our blog, website, or application is intended for reference and educational purposes only and is not intended to replace or substitute for any professional medical advice, diagnosis, treatment, or other professional advice. If you have specific concerns or a situation arises in which you require medical advice, you should consult with an appropriately qualified and licensed medical services provider.
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