Rebecca Valdez is a registered dietitian nutritionist and nutrition communications consultant, passionate about food justice, equity, and sustainability.

Isabel Casimiro, MD, PhD, is board-certified in internal medicine. She is an endocrinologist at the University of Chicago and is based in Chicago, Illinois.

Potassium is a mineral needed in small amounts for cell, nerve, and muscle function. Under normal circumstances, your body will automatically control potassium levels in your blood. Low potassium, also known as hypokalemia , can have many causes that result in mild to severe symptoms.

Low potassium levels are most frequently caused by certain medications or medical conditions, including gastrointestinal symptoms such as diarrhea and vomiting. While low potassium usually is not dangerous, severely low levels can cause serious complications that can affect your nervous and digestive systems and your heart.

This article discusses the symptoms, possible causes, diagnostic tests, and treatment strategies of low potassium. It also covers when to seek medical treatment for your symptoms.

In mild cases of low potassium, you may not have any symptoms. In more severe cases, symptoms of low potassium include:

While low potassium can result from not getting enough potassium in your diet, it is more likely caused by conditions in which your body excretes too much potassium, either from the gastrointestinal tract or your kidneys.

Low potassium can also occur due to transcellular shift, in which your cells take too much potassium from the bloodstream.

Some of the most common causes of low potassium are:

Low potassium levels are often associated with the use of certain medications. Diuretics, also known as water pills, are one of the most common classes of medications that can lead to low potassium. Diuretics treat many conditions, including high blood pressure, congestive heart failure, and pulmonary edema .

Diuretics help remove excess fluid from the body and increase urine flow. Potassium is also released through urine, so diuretics may sometimes cause too much potassium to leave the body.

Other medications that can cause low potassium are:

If you are experiencing symptoms of low potassium, talk to your healthcare provider. Low potassium should not be self-treated and usually requires a medical test to determine severity. Treatments for low potassium aim to increase potassium levels and resolve the underlying causes.

In mild cases, low potassium may be treated with oral potassium pills provided by your doctor. These may be in the form of potassium chloride (e.g., Klor-Con, K-tab), potassium phosphate (e.g., Neutra-Phos, K-Phos Neutral), or potassium carbonate (e.g., Effer-K, K-Bicarb). Your healthcare provider will determine which oral potassium supplement is appropriate for you. 

In severe cases, you may need to receive intravenous (IV) potassium in the hospital. This treatment raises levels much quicker than oral potassium supplementation but also carries a risk of inducing hyperkalemia, a condition in which potassium levels get too high.

Hyperkalemia can cause serious symptoms as well. Patients receiving IV potassium need to be closely monitored by their healthcare team.

Eating more potassium-rich foods can also help treat and prevent low potassium levels, though in many cases, you may not get enough from diet alone. Foods that are high in potassium include:

Though mild low potassium is not dangerous and can easily be treated with oral potassium supplementation, severely low potassium levels can cause serious complications. In severe cases of low potassium, life-threatening heart failure, paralysis, and respiratory failure can occur.

If you have a heart condition such as cardiac ischemia, heart failure, or left ventricular hypertrophy, low potassium levels are more likely to cause further cardiac problems. If this is the case, contact your doctor immediately if you are experiencing any symptoms.

Low potassium is diagnosed through a basic biochemical lab panel, which tests potassium levels in your blood and other compounds such as sodium, glucose, chloride, bicarbonate, blood urea nitrogen (BUN), and creatinine. If the reason for your low potassium is unclear, additional tests may be needed to determine the underlying cause.

To explain the cause of your low potassium, your healthcare provider may order the following tests:

Consult a healthcare provider to help assess your symptoms and determine if you have low potassium levels if you are experiencing any of the following symptoms:

Low potassium can be especially dangerous if you have an underlying heart condition. Seek treatment right away if you think your potassium levels may be low.

Low potassium (hypokalemia) symptoms depend on the severity of your case. Mild low potassium may show no symptoms, while more severe low potassium symptoms can include serious heart and neuromuscular complications. Many conditions and medications may cause low potassium, usually due to the body excreting too much potassium from your gastrointestinal tract or kidneys or causing a transcellular shift.

If you are experiencing symptoms of low potassium, seek medical care so a provider can test your blood levels. If your potassium levels are low, potassium supplementation with oral pills or intravenous infusion is the most common treatment. A diet that includes potassium-rich foods can help improve your potassium levels, but food alone is not usually sufficient to treat hypokalemia.

Having low potassium levels is a common health concern easily treated in most cases. However, it should still be taken seriously to prevent further problems, especially if you have an underlying heart condition. Once your healthcare provider diagnoses your low potassium, they will identify the best treatment strategy for you to help relieve symptoms and improve your potassium levels.

Common causes of low potassium include the use of diuretics, chronic diarrhea, and frequent vomiting. Insufficient intake, excessive losses, or transcellular shifts can all lead to low potassium levels.

Severe low potassium can lead to heart failure, especially in those with underlying heart conditions. If you are experiencing symptoms such as abnormal heart rhythm, palpitations, or chest pain, seek medical care right away.

Low potassium is treated through oral potassium supplements or intravenous (IV) potassium. Your healthcare provider will determine which supplementation is appropriate for you based on your levels and medical history. Eating potassium-rich foods may help improve your levels but is not usually enough to treat low potassium on its own.

You may not feel any symptoms if your potassium is mildly low. In more severe cases, low potassium may cause symptoms such as abnormal heart rhythms, muscle cramps or twitching, constipation, and fatigue. Talk to your healthcare provider if you are experiencing any of these symptoms.

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Kardalas E, Paschou SA, Anagnostis P, et al. Hypokalemia: a clinical update. Endocr Connect. 2018;7(4):R135-R146. doi:10.1530/EC-18-0109

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Dietary Guidelines for Americans. Food sources of potassium.

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