How Does Potassium Affect Heart Failure? (2024)

Potassium is an important mineral for sustaining life, but there is such a thing as "too much of a good thing." Learn the function of potassium in the body, why potassium homeostasis is key for heart health, and the different levels of potassium in food.

What Is Potassium?

Potassium is an essential electrolyte that your body, specifically your heart, nerves, and muscles, needs to work properly.

Potassium regulates a wide range of physiologic functions including muscle contraction, regular heartbeat, and the movement of nutrients into cells and waste products out of cells. A diet rich in potassium helps to offset some of sodium's harmful effects on blood pressure.

Potassium and Heart Health

The rhythmic contractions of the heart are controlled by periodic changes of the membrane potential, called action potentials, within the cells of the heart muscle (cardiac myocytes). Potassium is both essential to generating a regular heartbeat and stabilizing the heart, helping to stave off potentially deadly cardiac arrhythmias.

Most of the potassium that you need will be consumed in your diet. Foods high in potassium help manage your blood pressure by lessening the effects of sodium. Potassium does this through its ability to promote sodium excretion in urine and ease tension in your blood vessel walls.

Studies have shown that increasing potassium intake can reduce the risk of cardiovascular diseases, such as high blood pressure, heart disease, and stroke, but the mechanism responsible for this is unknown. Some researchers believe that potassium may prevent atherosclerosis, or hardening of the arteries, but more research is needed to support these claims.

Low Potassium Levels

Low potassium levels in the blood, also known as hypokalemia, can be due to a number of conditions including:

• Medicines, such as diuretics (water pills) or certain antibiotics
• Diarrhea or vomiting
• Eating disorders (such as bulimia)
• Hyperaldosteronism (over production of the male hormone aldosterone)
• Laxative overuse, which can cause diarrhea
• Chronic kidney disease
• Low magnesium level
• Excessive sweating (hyperhidrosis)
• Genetic disorders, such as hypokalemic periodic paralysis or Bartter syndrome

Mildly low potassium levels usually cause no symptoms, but larger decreases may cause the following symptoms:

• Weakness
• Fatigue
• Constipation
• Muscle twitches
• Muscle cramps or weakness
• Muscles paralysis
• Abnormal heart rhythms
• Kidney problems

High Potassium Levels

Having too much potassium in the blood, a condition called hyperkalemia, can be dangerous to your heart health. The kidneys are responsible for maintaining the balance of potassium in the blood. The following condition may put you at risk of hyperkalemia:

• Chronic kidney disease
• Diabetes
• Congestive heart failure
• Medications that disrupt potassium balance, such as certain blood pressure-lowering drugs
• Major burns or trauma to the body
• Chronic alcoholism
  

At first, you may not notice any symptoms, but hyperkalemia may cause symptoms of:

• Abdominal (belly) pain and diarrhea
• Chest pain
• Heart palpitations or arrhythmia (irregular, fast or fluttering heartbeat)
• Muscle weakness or numbness in limbs
• Nausea and vomiting

Dietary Sources of Potassium

Potassium is an essential nutrient that is naturally present in many foods and is present in all body tissues. Potassium levels are tightly regulated because it is required for normal cell function. This mineral helps to maintain the balance between intracellular fluid volume and transmembrane electrochemical gradients.

Although potassium supplements are available, most people can get the potassium they need from the food they eat and the fluids they drink. Dietary sources of potassium include:

• Apricots and apricot juice
• Asparagus
• Avocados
• Brown rice
• Cantaloupe and honeydew melon
• Coffee and tea
• Fat-free or low-fat (1%) milk
• Fat-free yogurt
• Most fish
• Milk
• Grapefruit and grapefruit juice (talk to your healthcare provider if you’re taking a cholesterol-lowering drug)
• Leafy greens like spinach and kale
• Halibut
• Lima beans
• Mushrooms
• Oranges and orange juice
• Peas
• Potatoes (white and sweet potatoes)
• Prunes and prune juice
• Raisins and dates
• Tomatoes, tomato juice, and tomato sauce
• Tuna

Planning a Low Potassium Diet

High potassium levels in the blood can cause serious heart troubles, especially if you are at high risk of heart failure, but before you severely restrict the potassium in your diet you may want to check in with a healthcare professional to talk about the risks of high potassium and how a low-potassium diet can help.

Talk to Your Healthcare Provider

If you are at high risk for hyper- or hypo- kalemia or experience any of the aforementioned symptoms, seek immediate medical attention. Dietary changes can help prevent and treat high or low potassium levels.

Talk to a healthcare professional to understand any risk you might have for hypo- or hyper- kalemia, as they may recommend foods that you may need to limit, avoid, or increase depending on your potassium status.

Summary

Potassium is good in the heart and is found abundantly in the foods we eat and fluids we drink but too much can cause serious heart problems, especially in those with diabetes, hypertension, or kidney disease, who are at high risk of heart failure. Before starting a low potassium, diet check in with a healthcare professional to safely plan your course.

A Word From Verywell

The body does a great job of tightly regulating potassium levels, and most of the time you won’t feel symptoms if your levels are slightly high or low. Even more, most U.S. adults get a healthy amount of potassium in their diet through milk, coffee, tea, other nonalcoholic beverages, bananas, avocados, and potatoes and do not have to make changes in their diets or use potassium supplements to meet their daily requirements.

If you have a condition that weakens your heart, that may not be the case. You may need to pay close attention to the amount of potassium you ingest. But before making any drastic changes to your diet, consult a healthcare professional who will help you adjust your diet in the safest way possible.