You can lower your potassium through dietary changes, cooking methods, medications, and in urgent situations, hospital treatments that work within minutes. The right approach depends on how high your levels are and what’s causing them. Normal blood potassium falls between 3.5 and 5.0 mEq/L, and levels above 5.5 are considered moderately high, while anything above 6.5 is severe and requires emergency care.
Start With What You Eat
Diet is the most direct lever you have. Potassium is found in nearly all foods, but some carry far more than others. High-potassium foods include bananas, oranges, potatoes, tomatoes, avocados, spinach (when cooked), beans, and dairy products. If you’ve been told to limit potassium, the goal is typically to swap these for lower-potassium alternatives rather than to cut entire food groups.
Fruits and vegetables with less than 200 mg of potassium per serving give you the most flexibility. Good options include apples (99 mg per cup of slices), blueberries (about 140 mg per cup), grapes (176 mg per cup), pears (162 mg per cup of slices), kale (73 mg per cup raw), cabbage, corn, carrots (150 mg per half cup frozen), cauliflower, and onions. Canned and drained fruit in light syrup also tends to be lower because some potassium leaches into the liquid you discard.
Portion size matters as much as food choice. A small serving of a high-potassium food can sometimes fit into your day, while eating large quantities of even a moderate-potassium food can add up. Reading nutrition labels helps, but potassium wasn’t required on labels until recently, so older products may not list it.
Watch for Hidden Potassium Sources
Salt substitutes are one of the most common hidden sources. Many products marketed as “low sodium” replace regular salt (sodium chloride) with potassium chloride. The FDA now allows manufacturers to label this ingredient as “potassium salt” to make it more obvious, but older products may still list it only as potassium chloride deep in the ingredient list. If you’re managing high potassium, check every seasoning blend, reduced-sodium soup, and “heart healthy” processed food for this swap.
Some medications and supplements also contain potassium. Certain antibiotics, blood pressure medications (particularly ACE inhibitors and potassium-sparing diuretics), and even over-the-counter supplements can raise your levels. Don’t stop any prescribed medication on your own, but make sure every provider you see knows you’re managing high potassium.
Cooking Methods That Reduce Potassium
Boiling vegetables in a large volume of water draws some potassium out of the food and into the cooking water, which you then discard. This works best when you cut food into small, thin pieces to increase surface area. Peeling root vegetables before boiling also helps, since potassium concentrates just below the skin.
One popular recommendation is to soak potatoes overnight in water before cooking them. However, research from the USDA found that overnight leaching had no significant impact on potassium reduction, contrary to what many diet guides suggest. Boiling diced potatoes in fresh water (not the soaking water) is more effective than soaking alone. Double-boiling, where you bring the food to a boil, discard the water, and boil again in fresh water, appears to pull out more potassium than a single boil.
Medications That Lower Potassium
When diet alone isn’t enough, doctors may prescribe medications that help your body get rid of excess potassium.
Potassium binders work in your gut. They trap potassium from the food you eat before your body can absorb it, and you pass it out in your stool. Two newer options are available: one approved in 2015 uses calcium to exchange for potassium ions in the digestive tract, and another approved in 2018 exchanges hydrogen and sodium for potassium. Both are taken as powders mixed into water and are designed for ongoing daily use rather than emergencies.
Certain diuretics increase potassium loss through urine. Loop diuretics are the type most commonly used for this purpose. They cause your kidneys to flush out more fluid, and potassium goes with it. These are the opposite of “potassium-sparing” diuretics, which are sometimes the reason potassium gets too high in the first place.
How High Potassium Is Treated in Emergencies
Severely elevated potassium (above 6.5 mEq/L) is dangerous because it can disrupt your heart’s electrical rhythm. Emergency treatment in a hospital typically happens in stages, each with a different purpose.
The first step is protecting the heart. An IV calcium solution stabilizes the heart’s cell membranes and starts working within one to three minutes, but its effect only lasts 30 to 60 minutes. It doesn’t lower potassium itself. It buys time for the next treatments to kick in.
The second step is shifting potassium out of the bloodstream and back into cells, where it’s safer. This is done with IV insulin (given alongside glucose to prevent low blood sugar) or inhaled medications similar to those used for asthma. Both take 30 to 60 minutes to start working. These treatments temporarily redistribute potassium but don’t remove it from the body.
The third step is actually removing potassium from the body, either through diuretics, potassium binders, or in severe cases, dialysis.
Exercise and Potassium Spikes
Intense physical activity can temporarily push potassium levels surprisingly high. During exercise, working muscles release potassium with every contraction, and blood levels can spike to around 8 mEq/L during sustained effort. That would be a medical emergency if it lasted, but it doesn’t. Once you stop exercising, your muscles reabsorb potassium within minutes, and levels normalize quickly. In fact, they can temporarily dip below normal before settling back.
This matters for two reasons. If you have a blood draw scheduled, vigorous exercise right beforehand could affect results. And if you already have chronically high potassium due to kidney disease or medication, intense exertion could push you into a dangerous range. Moderate, consistent activity is generally safer than sudden bursts of high-intensity effort.
Make Sure Your Results Are Accurate
Before making major changes, it’s worth knowing that falsely high potassium readings are common enough to have their own name: pseudohyperkalemia. Clenching your fist during a blood draw, leaving the tourniquet on for more than a minute, or rough handling of the blood sample can all release potassium from cells and inflate the result. Elevated white blood cell or platelet counts can also cause false readings.
If your potassium comes back high but you feel fine and have no obvious risk factors, a repeat test with careful technique (relaxed hand, minimal tourniquet time) can confirm whether the elevation is real. Many clinicians will order a redraw before starting treatment for borderline results.