Symptoms of Low Potassium and How to Treat It

Medically reviewed by Isabel Casimiro, MD, PhD

Knowing the symptoms of low potassium, or hypokalemia, may allow you to recognize a potassium deficiency if you develop one. 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 can have many causes that result in mild to severe symptoms. Among the most frequent causes are certain medications and 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 system, digestive system, and heart.

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

Symptoms of Low Potassium

In mild cases of low potassium, you may not have any symptoms. If you do, the symptoms of low potassium in these cases are usually mild to moderate and may include:

• Constipation

• Feeling of skipped heartbeats or palpitations

• Fatigue

• Muscle damage

• Muscle weakness or spasms

• Tingling or numbness

In more severe cases, low potassium may cause cardiac arrhythmia (abnormal heart rhythms), especially in people with heart disease. This could lead to lightheadedness or fainting. Very low potassium can be dangerous and may cause the heart to stop.

Causes of Low Potassium

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.

Low Potassium Due to Diet and Medical Conditions

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.

Aside from medications, some of the most common causes of low potassium include:

• Diarrhea or vomiting

• Eating disorders, including bulimia

• Hyperaldosteronism, when excess aldosterone hormone is released by the adrenal glands

• Chronic kidney disease

• Low magnesium level

• Sweating

• Genetic disorders, such as hypokalemic periodic paralysis and Bartter syndrome
  

• Osmotic diuresis, which is increased urination due to certain substances found in fluid filtered by the kidneys

• Mineralocorticoid excess, when high blood pressure is caused by one mutated gene from each parent

• Cushing’s syndrome, resulting from high exposure to cortisol

• Insulin administration

• Thyrotoxicosis, meaning excess thyroid hormones in the body

• Renal tubular acidosis, when kidneys are unable to get rid of enough acid, retain enough base, or both

Low Potassium Due to Medications

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 include:

• Antimicrobials including ampicillin, penicillin, aminoglycosides such as gentamicin

• Beta2-receptor agonists, including ProAir HFA (albuterol), Akovaz, (ephedrine), and EpiPen (epinephrine)

• Diuretics including Diamox (acetazolamide), Zaroxolyn (metolazone), and thiazides such as Zaroxolyn (metolazone)

• Insulin

• Mineralocorticoids and glucocorticoids including hydrocortisone, fludrocortisone, and prednisone

• Laxatives including Kayexalate (sodium polystyrene sulfonate), Arlex (sorbitol), and phenolphthalein

• Xanthines including theophylline and caffeine

Foods Rich in Potassium

Eating more foods high in potassium 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 the folliwng:

How to Treat Low Potassium

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. They include oral potassium supplements and 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.

Oral Potassium Supplements

In mild cases, low potassium may be treated with oral potassium pills provided by your healthcare provider. 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.

Intravenous Potassium

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.

Complications From Low Potassium

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

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 healthcare provider immediately if you are experiencing any symptoms.

Diagnosing Potassium Defficiency

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:

• Urine electrolyte test: This test will measure potassium and chloride levels in your urine to help determine if the cause is related to your kidneys.

• Arterial blood gas (ABG): This test can determine if you have metabolic acidosis or alkalosis, conditions where your body’s acid-base balance has been thrown off.

• Electrocardiogram (ECG): This test will check for abnormal heart rhythms caused by low potassium.

When to See a Healthcare Provider

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:

• Cardiac arrhythmia

• Muscle cramping

• Paralysis

• Respiratory problems

• Vomiting

• Excessive diarrhea

Talk to a healthcare provider if you are experiencing symptoms of low potassium.

Very 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.

Summary

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.

Read the original article on Verywell Health.