You can lower potassium through dietary changes, medications that help your body excrete it, or hospital treatments for dangerously high levels. Normal blood potassium falls between 3.5 and 5.0 mEq/L, and levels above 5.5 mEq/L are considered moderately elevated and typically need intervention. The right approach depends on how high your potassium is and how quickly it needs to come down.
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. The heart’s electrical pattern changes in a predictable sequence: first the T-waves on an EKG become tall and peaked, then the PR interval stretches out, and the QRS complex (representing the main heartbeat) widens. In severe cases, the heart’s electrical signals can degrade into a chaotic rhythm or stop entirely.
Mild elevations often cause no symptoms at all, which is why many people first learn about high potassium from a routine blood test. As levels rise, you might notice muscle weakness, tingling, nausea, or an irregular heartbeat. Because the jump from “no symptoms” to “cardiac emergency” can happen quickly, even modest elevations are taken seriously, especially if you have kidney disease.
Dietary Changes That Lower Potassium
For people with kidney disease, the typical daily target is 2,000 to 2,500 milligrams of potassium. Since a single baked potato can contain over 900 mg, hitting that target requires knowing which foods are potassium-heavy and which ones you can swap in.
Some of the biggest offenders and their lower-potassium alternatives:
- Bananas: Switch to apples, applesauce, or apple juice
- Potatoes: Try cauliflower instead
- Tomatoes (fresh, canned, sauce, soup): Use bell peppers or cucumbers
- Spinach: Choose iceberg or romaine lettuce
- Oranges: Opt for tangerines or clementines
- Milk: Use almond milk or rice milk
- Pinto or black beans: Swap for green beans or wax beans
One often-overlooked source: salt substitutes. Many brands replace sodium chloride with potassium chloride, which can meaningfully raise blood potassium in people whose kidneys don’t excrete it efficiently. If you have chronic kidney disease and use a salt substitute, check the label. Research published in The Lancet Global Health notes that the risk of a dangerous spike is highest when something suddenly impairs your ability to excrete potassium, like dehydration, an acute illness, or a new medication, on top of the extra potassium from the substitute.
Medications That Pull Potassium Out
Potassium Binders
Potassium binders are powders or suspensions you take by mouth. They work in your gut by trapping potassium so it passes out in your stool instead of being absorbed into your bloodstream. Two newer options are commonly prescribed. One (sold as Veltassa) works primarily in the lower colon and starts lowering potassium within 4 to 7 hours. The other (sold as Lokelma) acts throughout the entire digestive tract and can begin working in as little as 1 to 6 hours. Both are taken regularly to keep levels stable over days and weeks, not just for one-time emergencies.
Diuretics
Loop diuretics push your kidneys to excrete more potassium in your urine. They’re effective enough that low potassium is actually a well-known side effect, and many people on these medications need potassium supplements to avoid dropping too far. One large study found that patients on higher-dose loop diuretics who received potassium supplementation had a 16% lower risk of death compared to those who didn’t, highlighting just how aggressively these drugs can deplete potassium. For someone with high potassium and enough remaining kidney function, diuretics can be a useful tool.
Hospital Treatments for Dangerously High Levels
When potassium spikes to dangerous levels, usually above 6.0 to 6.5 mEq/L with EKG changes, treatment happens in layers, each doing a different job.
The first priority is protecting the heart. Intravenous calcium stabilizes the heart’s electrical membranes without actually lowering potassium at all. It raises the threshold that heart cells need to fire, which counteracts the destabilizing effect of excess potassium. If the EKG doesn’t improve within 5 to 10 minutes, the dose is repeated. This buys time for the next steps.
Next comes shifting potassium out of the bloodstream and into cells. The standard approach is an IV combination of insulin and glucose. The insulin drives potassium into cells; the glucose prevents your blood sugar from dropping dangerously low. This starts working within 20 to 30 minutes and can lower potassium significantly, though the effect is temporary since the potassium hasn’t actually left the body.
The final step is removing potassium from the body entirely, either through the kidneys (with diuretics, if they’re still functioning well enough) or through the gut (with potassium binders). For people whose kidneys can’t do the job, dialysis is the definitive treatment. A single conventional hemodialysis session removes roughly 70 to 100 mmol of potassium, and advanced filtration techniques can pull out even more, sometimes exceeding 200 mmol per session.
Common Causes Worth Addressing
Lowering potassium often means fixing whatever caused it to rise in the first place. The most common culprit is kidney disease, since healthy kidneys are your body’s primary potassium disposal system. But several medications also raise potassium as a side effect, including ACE inhibitors, ARBs, and certain “potassium-sparing” diuretics. If a medication is driving your levels up, your doctor may adjust the dose or switch to an alternative before adding more drugs to the mix.
Dehydration, tissue injury from burns or crush injuries, and uncontrolled diabetes can all release potassium from inside cells into the bloodstream, causing a temporary but sometimes dangerous spike. In these cases, treating the underlying problem is the most effective way to bring potassium back to normal.
Keeping Potassium Stable Long Term
If you’ve been told your potassium is elevated, the management plan typically involves some combination of dietary adjustments, medication review, and possibly a potassium binder taken daily. Regular blood draws to check your levels, often every few weeks initially, help your care team fine-tune the approach. For people on dialysis, potassium management is a permanent part of treatment, with levels checked before and after each session.
Cooking techniques also help. Boiling high-potassium vegetables in large amounts of water leaches some of the potassium out, a method sometimes called “leaching” or double-boiling. Draining the water and not using it for soups or sauces is key, since the potassium ends up in the liquid. This won’t turn a high-potassium food into a low-potassium one, but it can reduce the total amount meaningfully when applied consistently across meals.