Does potassium affect your blood pressure?

Hypertension—a blood pressure above 130 systolic/80 diastolic—is sneaky. It often doesn’t have any symptoms. When it does, the signs are easily confused for other things. You can feel dizzy, lightheaded, or have a pounding sensation in your head or chest. That’s why regular screenings for high blood pressure are incredibly important. The condition can cause heart disease, heart attacks, kidney disease, or even stroke when unnoticed and untreated.

Luckily, when diagnosed there are many simple changes you can make to decrease your blood pressure. There are often more options than just taking antihypertensive medications. Some of the most effective strategies are lifestyle changes, which include exercise, weight loss, quitting smoking, and eating a balanced diet—complete with the right amounts of certain vitamins and minerals. That includes decreasing salt intake and making sure you’re getting enough potassium. What’s the connection between potassium and blood pressure? It’s a powerhouse mineral that helps relax your vascular system, which lowers your blood pressure.

RELATED: Is salt bad for you?

How does potassium lower blood pressure?

Potassium and blood pressure have an inverse relationship to one another. “Patients with elevated potassium [tend to] have lower blood pressure, and patients who have low potassium [tend to] have an elevated blood pressure,” says Craig Beavers, Pharm.D., a member of the American College of Cardiology (ACC)’s Cardiovascular Team Section and Leadership Council and director of cardiovascular services at Baptist Health Paducah. Why? It has to do with the relationship between electrolytes and fluid in your body.

Potassium, sodium, and magnesium are all examples of electrolytes that help maintain the proper fluid and blood volume balance in your body. The role of sodium in high blood pressure is well-known. Too much salt can result in elevated blood pressure in susceptible individuals. Low potassium intake can have the same effect.

That’s because potassium helps kick sodium out of your system. The more potassium you eat, the more sodium you lose through your urine, according to the American Heart Association. If you’ve got a lot of sodium in your system, it can lead to fluid retention— and that makes your heart work harder because there’s more fluid to push around. That harder work raises your blood pressure and increases your risk for cardiovascular disease.

“If you’re losing sodium [by increasing potassium], you’re also losing some water,” says Dave Dixon, Pharm.D., member of ACC’s Prevention Section and Leadership Council, and Interim Chair of the Department of Pharmacotherapy and Outcomes Science at VCU School of Pharmacy. “By getting rid of that extra volume or fluid, it’s going to help your body maintain a little bit better blood pressure. Potassium also helps your blood vessels relax a little bit more, and since the blood vessels are more relaxed, the pressure inside them is lower.”

RELATED: What causes hypokalemia (low potassium)?

How much potassium do you need to lower blood pressure?

For the average adult, a healthy potassium intake is between 3,500 and 4,700 milligrams per day. Unfortunately, the typical diet in the U.S. offers too much sodium and not enough potassium. The first step to decreasing your risk factors for hypertension is decreasing salty food intake and adding potassium-rich foods to your diet. It is a good idea to have your labs checked with your physician to see if you are deficient in potassium or have elevated levels, which can happen with chronic kidney disease. 

What should you eat to increase potassium?

The best way to increase your levels is through dietary potassium, meaning from the food you’re eating. Try adding more of these foods to your high-potassium diet:

• Bananas
• Avocados
• Citrus fruit
• Leafy greens
• Sweet potatoes and regular potatoes, plus the skins
• Dairy products
• Fish
• Beans

Depending on your lifestyle and health, these may help your blood pressure, but they may not be a cure-all.

Should you take supplements?

For some people increasing potassium intake with food might not be enough. In that case, potassium supplements are available both over the counter and by prescription, but it’s important to take them safely. For some people, doing a high potassium diet and supplementation can push your potassium level into a dangerously high range (more on that below).

“The key is to have proper communication with your healthcare clinician about whether  potassium supplementation is right for you and [how much] of it you would need,” Dr. Beavers says. Over-the-counter vitamins generally have low doses, but be sure not to exceed the labeling instructions. If you have acid reflux, potassium supplements may irritate your esophagus. Make sure you drink plenty of water and sit upright for at least 30 minutes after taking potassium supplements.

Generally, every type of potassium (potassium chloride, potassium citrate, potassium gluconate, potassium bicarbonate, potassium aspartate, and potassium orotate) can be used as a supplement or to help lower blood pressure, but the most common are potassium chloride, citrate, and gluconate.

Can you have too much potassium?

It is possible to have too much potassium. This is a particular concern in people with chronic kidney disease (CKD). An excess can lead to a condition called hyperkalemia, and it’s a serious concern. Dr. Beavers notes that it can cause electrical malfunctions in your heart, and it can eventually begin to stiffen and calcify your arteries. It can also lead to kidney damage when your urinary system is unable to eliminate the excess.

If you’re worried you’re taking too much potassium, watch out for these warning signs:

• Heart palpitations
• Quick heartbeat
• Chest pain
• Abdominal pain
• Diarrhea
• Muscle pain or cramping
• Muscle weakness
• Paralysis (in extreme cases)
• Nausea
• Vomiting

Too high potassium levels can be a sign of underlying kidney disease or even renal failure. If you experience any of these symptoms and aren’t taking a potassium supplement or eating a lot of potassium, your potassium excretion may be impaired. If this is the case, talk to your healthcare provider.

Which medications interact with potassium?

Typically, medications don’t tend to interact with potassium. But it’s important to know that some medication can increase or lower your potassium levels. ACE inhibitors, spironolactone, and antiretroviral drugs all increase your potassium, Dr. Dixon says. Diuretics can decrease your potassium. Even though there’s no direct potassium-to-medication interaction, check with your physician to see how your prescriptions are already affecting your potassium levels before you decide to supplement.

RELATED: What are potassium-sparing diuretics?

How long does it take for potassium to lower blood pressure?

It’s important to recognize the effect of potassium is not immediate. It’s not like you can eat a banana and then—boom—five minutes later, you’re less hypertensive, with lower cardiovascular risk.

And, dietary approaches don’t work in all circumstances. “If we have someone that’s in the emergency room with high blood pressure, we’re not going to push potassium,” explains Dr. Dixon. “It’s going to be a couple different blood pressure lowering drugs that would be much more effective in that case.”

It will take weeks to months to lower blood pressure using potassium. That’s why eating a balanced diet and changing your lifestyle to prioritize heart health over the long haul is important. If you eat properly, you’ll likely get enough potassium just through your food. The best option is to combine that diet with other actionable steps to maintain healthy blood pressure levels: getting regular exercise, avoiding cigarettes, maintaining a healthy weight, and decreasing sodium intake.

RELATED: How to lower blood pressure quickly and naturally

“If we’re all fortunate enough to live into our late 70s or into the eighth and ninth decade of life, at some point your blood pressure may creep up a little bit and meet that threshold of hypertension,” Dr. Dixon says. “But there’s a lot we can do in our younger years to delay that as much as possible and hopefully prevent it.”