You probably know your blood pressure — or at least have it checked regularly. There’s a good chance you’ve had your cholesterol level tested, and are up to speed on your bad “LDL” cholesterol number. And with diabetes a looming concern, many Americans routinely have their blood-sugar checked. After all — among other risks posed — having any of these numbers out of whack can be associated with potentially life-threatening heart problems.

However, for about 2 to 3 percent of the general population and up to half of those with chronic kidney disease, another serious, measurable medical issue potentially threatens their heart health: high potassium, or hyperkalemia. Potassium is removed from the body by the kidneys, so anything that compromises kidney function can lead to hyperkalemia. “Ultimately, high potassium could stop your heart,” says Dr. Thomas Golper, a nephrologist at Vanderbilt University Medical Center in Nashville. Though the tolerance for potassium differs somewhat from patient to patient and medical opinions vary on what’s consider optimal, a potassium level of about 3.6 to 5.2 millimoles per liter of blood is generally considered normal; a millimole is one-thousandth of a mole, a chemistry unit measuring the mass of elements. A potassium level that exceeds 7.0 mmol/L can be dangerous, according to Mayo Clinic, requiring immediate treatment.

In severe cases, when left untreated, the level of potassium can rise dangerously high and cause heart rhythm abnormalities that prove fatal, says Dr. James Udelson, chief of the division of cardiology at Tufts Medical Center in Boston. “It could be something like ventricular flutter or ventricular fibrillation or cardiac standstill — the rhythm just stops,” he says.

“To be clear, it does not happen too often, because usually high potassium is caught before that,” Udelson says. But even at lower levels, elevated potassium may cause muscle weakness and result in changes on an electrocardiogram, or ECG, which is often performed if a patient is suspected of having hyperkalemia. This test can identify heart rhythm problems, or cardiac arrhythmias.

High potassium levels can also complicate treatment for heart failure, since drugs used to treat heart failure — like ACE inhibitors — can drive potassium levels even higher in some patients, says Udelson. He’s hopeful that a drug newly approved in October by the Food and Drug Administration called Veltassa, manufactured by Relypsa of Redwood City, California, could provide another option for keeping a patient’s potassium level in check, while aggressively treating the heart failure with other medication. That is “in theory,” he says of the drug, which he expects to be available for clinical use soon. “The FDA approvals have really been about just lowering potassium in people in whom it’s elevated, who have kidney disease, either on its own, [with] diabetes or in conjunction with heart failure. So the idea of using them to allow better doses of heart failure drugs is somewhat speculative.” He expects this to be tested in the future, however.

Because of the drug’s delayed onset of action, or the time required for it to take effect in a patient, the FDA says it shouldn’t be used as an emergency treatment for life-threatening hyperkalemia. However, the agency indicated that the powdered medication, which patients can mix with water and drink, could be a viable option for treating people with hyperkalemia, before the problem gets out of hand.

“Hyperkalemia typically occurs in patients with acute or chronic kidney disease or heart failure, particularly in those who are taking drugs that inhibit the renin-angiotensin-aldosterone system, which regulates blood pressure and fluid balance in the body,” the FDA said in a statement. Medications that inhibit this system include ACE inhibitors and beta blockers used to treat heart problems. In clinical trials, the agency found Veltassa was effective in lowering potassium levels in people with hyperkalemia who had chronic kidney disease and were on at least one drug that inhibited the renin-angiotensin-aldosterone system.

The drug may also provide an effective alternative to the hard-to-stomach, granular medication Kayexalate, prescribed to some patients to knock down potassium levels. In addition to being difficult to tolerate physically, Golper says the granules can get caught in tiny pockets in the bowel and have been, in rare cases, associated with bowel injury.

That hasn’t occurred with Veltassa, also called Patiromer, which Golper points out is a powder. But he notes that FDA trials only included a few thousand patients, and experts say the full range of potential benefits and harms won’t be known until more patients take it. For now, the FDA says the most common adverse reactions to the drug includes constipation, nausea, abdominal discomfort — and flatulence. More seriously, it was also found to be associated with decreased magnesium levels in the blood, or hypomagnesemia. Hypomagnesia can disrupt organ function and cause complications including one of the very issues that lowering potassium seeks to avoid: heart arrhythmias. In addition, the FDA put a black-box warning on the drug — the strongest caution issued by the agency — noting that the drug binds to other meds taken orally, and that it and other oral drugs should, as a result, be taken at least six hours apart.

Clinicians say, too, that the cost of the drug — which is not yet known — will also affect how widely it’s prescribed.

Nor is taking medication an inevitable solution for patients with high potassium. For many patients with mild or borderline high potassium, changes in diet alone may be enough to bring it back to a normal, healthy range, Golper says. That may involve simple changes like avoiding melons, oranges and peaches — which all contain potassium — in favor of eating more apples, which don’t contain potassium, he says.

Other foods — like tomatoes — may be more difficult for some to part with, he notes, while cutting down on barbecue sauce and potatoes can also help. In addition, there are food-prep tricks that help reduce potassium in certain items, like potatoes. “Soaking or boiling leeches the potassium out,” Golper says.

He also sometimes recommends diuretics to help flush out potassium, further lowering a person’s levels. “Some people have high potassium because their kidneys don’t excrete acid properly, and the acid combines with the body in a way that makes the potassium go up. That’s easy to treat. You just giving them an alkalizing agent, like baking soda,” he says, which can be taken in tablet form or out of the box mixed with water.

Many tolerate mild or slightly high potassium just fine and are asymptomatic. But levels can increase, experts say, so it’s still important to talk with a doctor about the issue. Dr. Charles Wingo, professor of medicine at the University of Florida in Gainesville, says that, among other conditions, anyone who has high blood pressure, heart disease, diabetes and chronic kidney disease should have their potassium levels checked (which can be done through a simple blood test) particularly if they are on certain drugs. As the FDA notes, those would include drugs that inhibit the renin-angiotensin-aldosterone system. “The person’s physician should be the one to make the decision to check the potassium,” Wingo says.

Experts say it’s important to treat any underlying medical issues that may be causing or contributing to high potassium. “Hyperkalemia is frequently observed in chronic kidney disease,” Wingo says, as well as other conditions, such as heart disease and diabetes. “It’s important to catch abnormal kidney function early so that it can be treated.”

Patients are often referred to a nephrologist for treatment. By seeing a doctor to ferret out the root cause of hyperkalemia, experts say patients can move forward with their physician to find a solution. “That’s the No. 1 thing to do about high potassium,” Golper says. “See if you can figure out why it’s high.”

More from U.S. News

The 10 Best Heart-Healthy Diets

Got Diabetes? Why You Must Protect Your Feet

The 10 Best Exercises You Can Do for the Rest of Your Life

Heartfelt Concern: Do You Have High Potassium? originally appeared on usnews.com