High potassium, called hyperkalemia, is managed through a combination of dietary changes, medication adjustments, and in urgent cases, medical treatment. Potassium levels above 5.5 mEq/L are considered moderately high, and levels above 6.5 mEq/L are severe and potentially life-threatening. Most people searching for ways to lower potassium will benefit most from food choices and awareness of hidden sources, but understanding the full picture helps you act appropriately based on how elevated your levels are.
Why High Potassium Is Dangerous
Potassium controls the electrical signals that keep your heart beating in rhythm. When levels climb too high, those signals become erratic. Mild elevations may cause no symptoms at all, which is part of what makes hyperkalemia tricky. As levels rise, you might notice muscle weakness, numbness, tingling, or nausea.
Severe hyperkalemia can come on suddenly and cause chest pain, heart palpitations, and irregular heartbeat. At its worst, it can trigger a heart attack. This is why any blood test showing potassium above 6.0 mEq/L typically prompts urgent treatment rather than dietary adjustments alone.
Common Causes Worth Knowing
The kidneys are responsible for filtering excess potassium out of your blood, so kidney disease is the most common underlying cause. Both acute kidney injury and chronic kidney disease reduce your body’s ability to clear potassium efficiently. Dehydration also impairs this process, concentrating potassium in the blood.
Several widely prescribed medications raise potassium levels. ACE inhibitors and angiotensin receptor blockers, commonly used for blood pressure, reduce the kidneys’ ability to excrete potassium. Beta blockers can do the same. Taking too much potassium through supplements is another straightforward cause. Type 1 diabetes and Addison’s disease (a condition affecting the adrenal glands) also contribute to potassium retention.
If your potassium is elevated, your doctor will likely look at your medication list first. Sometimes switching a blood pressure drug or adjusting a dose is enough to bring levels back to normal without any other changes.
Foods That Keep Potassium Low
The most effective long-term strategy for managing potassium is choosing foods with less than 200 mg of potassium per serving. The National Kidney Foundation provides detailed guidance on this, and the options are broader than most people expect.
For fruit, good choices include apples, berries (blueberries, strawberries, raspberries, blackberries, cranberries), grapes, pineapple, peaches, pears, watermelon (kept to one cup), and tangerines. Canned fruit in juice tends to be lower in potassium than fresh for some varieties, like apricots.
For vegetables, you have plenty to work with: green beans, broccoli (raw), cabbage, cauliflower, corn, cucumber, eggplant, kale, lettuce, mushrooms, onions, peppers, peas, zucchini, and yellow squash. These all fall under the 200 mg threshold per half-cup serving.
Starches like white rice, pasta, noodles, and non-whole-grain bread are also low in potassium. This is one case where refined grains are actually the better choice over whole grains, which contain more potassium.
High-Potassium Foods to Limit
Bananas get all the attention, but several common foods pack even more potassium. Potatoes, tomatoes, spinach, avocados, beans, lentils, and dried fruits are all high-potassium staples. Dairy is another significant source: a single cup of milk contains roughly 370 to 450 mg of potassium regardless of fat content, and chocolate milk is no better.
Beverages are an overlooked source. Orange juice is one of the most potassium-dense drinks available, with a cup of reconstituted frozen concentrate delivering over 1,600 mg. Tomato juice and vegetable juice cocktails run around 470 to 530 mg per cup. Pomegranate juice clocks in at 533 mg per cup. If you’re watching potassium, water is your safest drink. Coffee and tea are acceptable in limited amounts: the National Kidney Foundation suggests keeping coffee to 8 ounces and tea to 16 ounces per day.
The Double-Boiling Trick for Vegetables
If you love potatoes, sweet potatoes, or other root vegetables and don’t want to eliminate them entirely, a technique called leaching can pull a meaningful amount of potassium out before you eat them. Peel the vegetable, cut it into small pieces to increase surface area, then boil in a large pot of water. Drain, rinse, and boil again in fresh water.
This double-cooking method is significantly more effective than boiling once. In a study on root vegetables, single boiling left 92% of vegetables above 200 mg of potassium per 100 grams. Double boiling dropped that to 54%, nearly cutting the failure rate in half. Simply soaking vegetables in water without boiling does not remove meaningful amounts of potassium.
Salt Substitutes: A Hidden Trap
Many people with high blood pressure switch to salt substitutes, not realizing these products replace sodium chloride with potassium chloride. The potassium content is staggering. Just a quarter teaspoon of Nu-Salt contains 780 mg of potassium. No Salt has 650 mg, and Morton’s Salt Substitute has 610 mg in the same tiny amount. Even “lite” salt blends like Morton’s Lite Salt deliver 350 mg per quarter teaspoon.
If you need to limit both sodium and potassium, seasoning blends that use herbs and spices instead of potassium chloride are the safer option. Mrs. Dash, for example, contains only 5 to 15 mg of potassium per quarter teaspoon.
Medications That Lower Potassium
When dietary changes aren’t enough, doctors may prescribe a potassium binder. These medications work in your intestines by attaching to potassium and trapping it in stool so it leaves your body when you have a bowel movement, rather than being absorbed into your bloodstream. Three are currently available: patiromer (Veltassa), sodium zirconium cyclosilicate (Lokelma), and sodium polystyrene sulfonate (Kionex). These are typically taken daily and are used for ongoing management rather than emergencies.
Diuretics, often called “water pills,” can also help by increasing potassium excretion through urine. Not all diuretics work the same way, though. Some are “potassium-sparing,” meaning they actually raise potassium. Your doctor will choose the right type based on your situation.
What Happens in an Emergency
Severely elevated potassium, especially with heart rhythm changes, is treated in a hospital. The immediate goal is protecting the heart while bringing potassium down. Calcium is given through an IV to stabilize heart rhythm within minutes, though it doesn’t lower potassium itself. Insulin combined with glucose is then used to push potassium from the bloodstream into cells, providing a temporary but rapid drop. Blood sugar is monitored closely afterward. Potassium binders and other treatments follow to actually remove the excess from the body.
This level of intervention is reserved for potassium readings above 6.5 mEq/L or when an EKG shows characteristic changes like tall, peaked T-waves. It’s not something you manage at home, and if you’ve been told your potassium is dangerously high, treatment is typically handled the same day.
Practical Daily Habits
Staying hydrated helps your kidneys flush potassium more effectively, assuming your kidneys are functioning reasonably well. Spreading your potassium intake across meals rather than concentrating it in one large serving also reduces the peak load your body has to process at once.
Reading nutrition labels becomes essential if you’re managing potassium long-term. Since 2020, potassium has been required on U.S. nutrition labels, making it easier to track. Aim to identify your highest-potassium habits first. For many people, it’s a daily glass of orange juice, a banana, or liberal use of salt substitute. Replacing even one or two of those habits can make a measurable difference in your next blood test.