High potassium, known as hyperkalemia, is manageable through a combination of dietary changes, medication adjustments, and medical treatments depending on severity. Normal blood potassium falls between 3.5 and 5.0 mEq/L. Levels above 5.5 mEq/L are considered elevated, and anything at or above 7.0 mEq/L is a medical emergency that can cause dangerous heart rhythm changes.
Why Potassium Levels Rise
Your kidneys handle roughly 90% of the potassium your body needs to get rid of. When kidney function declines, potassium builds up in the blood. Chronic kidney disease is the most common underlying cause, but it’s far from the only one. Several widely prescribed medications raise potassium as a side effect: ACE inhibitors and ARBs (common blood pressure drugs), potassium-sparing diuretics, NSAIDs like ibuprofen, and certain heart medications. Using two of these drug classes together, particularly an ACE inhibitor with an ARB, raises the risk significantly.
Other contributors include uncontrolled diabetes, severe dehydration, significant tissue injury (like burns or crush injuries), and adrenal gland problems. Sometimes the cause is straightforward: eating very large amounts of high-potassium foods when your kidneys can’t keep up.
Dietary Changes That Lower Potassium
If your levels are mildly elevated, dietary adjustments are often the first and most effective step. The goal is to swap high-potassium foods for lower-potassium alternatives without making your diet miserable.
Fruits with less than 200 mg of potassium per serving give you plenty of variety. Blueberries come in at just 57 mg per half cup. Strawberries have 127 mg, grapes 88 mg, and a small apple 159 mg. Canned peaches (91 mg per half cup) and pineapple (78 mg) are also solid choices. Cranberries and cranberry juice are among the lowest options available, at 40 mg and 23 mg respectively. By contrast, bananas, oranges, and dried fruits pack 300 mg or more per serving and are worth limiting.
For vegetables, cabbage (73 mg cooked), green beans (72 to 105 mg), cucumber (76 mg), eggplant (61 mg), and cauliflower (88 mg cooked) are all lower-potassium options. Lettuce, both iceberg and romaine, runs about 116 mg per cup. Onions, bell peppers, and corn are also reasonable choices. The vegetables to watch out for are potatoes, tomatoes, sweet potatoes, and cooked spinach, all of which can deliver 400 mg or more per serving.
A few preparation tricks help too. Leaching, which involves peeling and soaking root vegetables in water for several hours before cooking, pulls some potassium out. Boiling vegetables in a large volume of water and draining it also reduces potassium content more than steaming or microwaving does.
Medications That Help
When diet alone isn’t enough, your doctor may prescribe a potassium binder. These are oral medications that work in your gut, trapping potassium from food and carrying it out in your stool before it reaches your bloodstream. Two newer options have largely replaced the older binder (sodium polystyrene sulfonate), which had a poor taste and gastrointestinal side effects.
Patiromer (brand name Veltassa) is typically started at 8.4 grams once daily, with the dose adjusted weekly as needed up to 25.2 grams. Sodium zirconium cyclosilicate (Lokelma) starts at a higher initial dose of 10 grams three times daily for up to 48 hours to bring levels down quickly, then drops to 10 grams once daily for maintenance. Both are designed for ongoing use in people with chronically elevated potassium, particularly those who need to stay on medications like ACE inhibitors that raise potassium as a side effect.
Loop diuretics, such as furosemide, are another tool. They work by forcing the kidneys to excrete more sodium and water, and potassium goes along with it. These are especially useful when fluid overload is also a concern, as in heart failure. However, they require adequate kidney function to work well.
Reviewing Your Current Medications
If you’re taking any medication that raises potassium, adjusting or switching it can make a meaningful difference. The most common culprits are ACE inhibitors (like lisinopril), ARBs (like losartan), aldosterone blockers (like spironolactone), potassium-sparing diuretics, NSAIDs, and certain antibiotics like trimethoprim. Even heparin and cyclosporine can contribute.
This doesn’t necessarily mean stopping a medication that’s important for your heart or blood pressure. Often, lowering the dose, switching to an alternative in the same class, or adding a potassium binder lets you keep the benefit while controlling potassium. The key is making sure every prescriber you see knows your potassium runs high, so no one inadvertently adds another potassium-raising drug to the mix.
When High Potassium Becomes an Emergency
Potassium above 7.0 mEq/L is dangerous because it disrupts the electrical signals that keep your heart beating in rhythm. The earliest sign on an EKG is tall, peaked T waves. As levels climb further, the heart’s electrical conduction slows: the P wave (which represents the upper chambers firing) flattens and disappears, the QRS complex (representing the main heartbeat) widens, and the risk of cardiac arrest rises sharply. These changes typically become prominent between 7.0 and 8.0 mEq/L.
Emergency treatment in a hospital follows a specific sequence. Calcium is given intravenously first, not to lower potassium itself but to stabilize the heart muscle against dangerous rhythms. Then, treatments that shift potassium from the blood into cells are used to buy time. Insulin combined with glucose is the standard approach, working within 20 to 30 minutes and lasting 2 to 6 hours. Inhaled albuterol at high doses (much higher than what’s used for asthma) also shifts potassium into cells and is sometimes used alongside insulin. Finally, measures to actually remove potassium from the body are started: diuretics if the kidneys are still functioning, potassium binders, or dialysis if kidney function is severely impaired.
Monitoring and Staying on Track
If you’ve had one episode of high potassium, regular blood work becomes part of your routine. How often depends on the cause. People with stable chronic kidney disease on consistent medications might check every one to three months. Anyone starting or adjusting a medication known to raise potassium should have levels rechecked within one to two weeks.
Symptoms of high potassium are unreliable as a warning system. Mild to moderate elevations often cause no symptoms at all. When symptoms do appear, they tend to be vague: muscle weakness, fatigue, numbness, or tingling. Nausea and a slow or irregular heartbeat can occur at higher levels. Because you can’t feel your potassium creeping up, lab monitoring is the only reliable way to catch it before it becomes dangerous.