Potassium is an essential mineral and an electrolyte that plays various roles in maintaining good health. It’s widely available in healthy foods, especially fruits and vegetables, but some people may not get enough. In addition, some health conditions and medications can cause low potassium levels.
Keep reading to learn more about the role of potassium, low potassium symptoms, and how to raise potassium levels if necessary.
What is Potassium’s Role in Your Body?
Every cell in your body requires potassium. As an electrolyte, it works closely with sodium and other electrolytes to maintain normal fluid balance inside and outside your cells. Potassium also helps regulate your:
- Blood pressure.
- Bone health.
- Heart rate and rhythm.
- Insulin function.
- Muscle contraction.
- Nerve function.
Your body maintains blood potassium levels within a very tight range. A normal potassium level for adults is 3.5 to 5.2 milliequivalents per liter (mEq/L) or millimoles per liter (mmol/L).
When you take in more potassium than you need, your kidneys remove the excess, and you excrete it in your urine. If you don’t eat enough potassium-rich foods, healthy kidneys can adjust the amount removed.
High or low potassium levels can cause serious health problems, including an irregular heartbeat.
What Causes Low Potassium?
Low potassium, also known as hypokalemia, means your blood potassium is less than 3.5 mEq/L (<3.5 mmol/L). It can happen if your diet is low in potassium, but more often, low potassium happens because of:
- Adrenal gland problems — Your adrenal glands make hormones that help balance potassium.
- Certain medications — Medications like diuretics (water pills) or laxatives often cause low potassium levels. Taking too much insulin can also lower your potassium levels.
- Digestive disorders — Excreting potassium in your stool is normal, but digestive disorders like inflammatory bowel disease or chronic diarrhea may cause excess potassium loss.
- Eating disorders, especially bulimia — People with eating disorders may not eat enough potassium, or they can lose excess potassium through vomiting or laxative use.
- Excess sweating — You typically lose small amounts of potassium in sweat. You can lose too much potassium if you’re working out in very hot weather for long periods and sweating heavily.
- Kidney disease — Healthy kidneys help regulate potassium levels in your blood. If your kidneys aren’t working normally, you may have low (or high) potassium levels.
- Low magnesium levels — Electrolytes like magnesium, sodium, and potassium work together and must stay balanced. If one is too high or low, it can affect other electrolyte levels. Low magnesium levels can cause a drop in potassium.
- A stomach virus — A stomach virus that causes severe vomiting and diarrhea can cause you to lose significant potassium. This is a common cause of low potassium in otherwise healthy people.
What Are Signs of Low Potassium?
A moderately low potassium level doesn’t always cause symptoms. But it may cause these or other mild symptoms that often develop slowly:
- Constipation.
- Fatigue or extreme tiredness.
- Heart palpitations or feeling like your heart skips a beat.
- Muscle weakness.
- Numbness or tingling in your hands, arms, legs, or feet.
If your potassium drops suddenly or your levels become very low, you could experience these more severe symptoms:
- An abnormal heart rhythm (arrhythmia) — If left untreated, this can lead to a heart attack or stroke. Call your doctor if you feel like your heart is skipping beats or beating too fast or slow.
- Lightheadedness or dizziness.
- Low blood pressure — Having blood pressure that’s too low may also cause lightheadedness, disorientation, or fainting.
- Muscle cramps or twitches.
- Sudden severe muscle weakness or paralysis.
Severely low potassium levels are dangerous and possibly life-threatening. Call your doctor if you have any of these symptoms.
A health care provider can check your potassium level with a blood or urine test in their office. They may also order a 24-hour urine test to see how much potassium you’re excreting in your urine. Your doctor will tell you how to collect urine at home over 24 hours.
No at-home test can monitor your potassium level.
How Are Potassium and Heart Health Connected?
One of potassium’s most important roles is supporting normal heart function and cardiovascular health. It helps the heart’s nerves and muscles work correctly, allowing the heart to beat at a strong and steady pace.
Potassium helps maintain healthy blood vessels and blood pressure. It dilates or expands blood vessels as blood pumps through them. By increasing the amount of sodium excreted, potassium counters the effects of eating too much sodium.
Diets high in sodium can raise blood pressure in many people, but eating more potassium-rich foods can help reduce blood pressure.
If you have a history of heart problems, talk to your doctor about your potassium needs. They can tell you how to get the right amount of this mineral through diet and, if necessary, a supplement.
They can also alert you to any symptoms that indicate a drop in potassium, like a heart arrhythmia or muscle cramps. If you take the heart medication digoxin, low potassium levels can increase the risk of digitalis toxicity. Taking too much of this medication can cause heart arrhythmias, vomiting, and yellowish vision or halos.
How Do I Raise My Potassium Levels?
Most healthy men need 3,400 milligrams of potassium daily. Women should get 2,600 milligrams a day. You may need more if you take medication or have a health condition that causes you to lose potassium.
Eating a potassium-rich diet can help ensure normal potassium levels. Most fruits and vegetables are high in potassium. These are excellent sources:
- Acorn squash
- Bananas
- Chicken breast
- Dried apricots
- Kidney beans
- Lentils
- Milk
- Orange juice
- Prunes
- Raisins
- Spinach
Electrolyte replacement beverages also provide potassium along with other electrolytes. These can help increase potassium levels quickly. They’re a great choice if you have a stomach virus or are exercising or sweating heavily and need to replace lost potassium.
Sometimes, your doctor might recommend IV potassium or a daily potassium supplement to maintain healthy levels. Following the dosing instructions on supplements is crucial because taking too much potassium is as harmful as getting too little.
Editor's Note: This article was originally published on , and was last reviewed on .