Hypokalemia occurs when the potassium levels in your blood are too low. Very low potassium levels can cause problems with your heart, kidneys, and muscles. Although hypokalemia is rare in healthy people, it can be caused by illness, medications, or kidney problems.
The experts at UPMC can help you find the cause of your low potassium levels, develop a treatment plan, and track your condition over time if needed.
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What Is Hypokalemia?
Potassium is an electrolyte, or mineral, that you get from food. It helps your body function properly. Your kidneys help to regulate the amount of potassium in your blood.
Hypokalemia occurs when the potassium levels in your blood are too low. Very low potassium levels can cause problems with your heart, kidneys, and muscles.
What are the severity types of hypokalemia?
There are three severity types of hypokalemia based on the potassium levels in your blood. The normal range for potassium levels in an adult is 3.5 to 5.2 milliequivalents per liter (mEq/L).
Types of hypokalemia include:
- Mild hypokalemia — Blood potassium levels of 3.0 to 3.4 mEq/L.
- Moderate hypokalemia — Blood potassium levels of 2.5 to 2.9 mEq/L.
- Severe hypokalemia — Blood potassium levels of less than 2.5 mEq/L.
Low potassium symptoms can be hard to identify. If you have mild hypokalemia, you may not even have any symptoms. Signs of low potassium are sometimes vague and easily mistaken for other problems.
Symptoms of low potassium may take weeks or months to appear. Mild low potassium symptoms include:
- Constipation.
- Fatigue.
- Muscle weakness.
- Tingling or numbness in your hands or feet.
What causes hypokalemia?
Hypokalemia can be caused by illness, medications, or kidney problems.
Common causes include:
- Chronic kidney disease.
- Eating disorders that lead to malnutrition.
- Excessive sweating.
- Genetic disorders, such as hypokalemic periodic paralysis or Bartter syndrome.
- Hypomagnesemia — low levels of magnesium.
- Overuse of medications such as diuretics, antibiotics, laxatives, and insulin.
- Problems with hormones produced by your adrenal glands.
- Severe vomiting or diarrhea.
Hypokalemia risk factors
You may be at a higher risk for hypokalemia if you have:
- An adrenal gland disorder. High aldosterone levels (hyperaldosteronism) or Cushing’s syndrome can lead to low potassium levels.
- An alcohol use disorder, or what people used to call alcohol addiction or alcoholism.
- Chronic kidney disease, especially in the early stages.
- An eating disorder such as bulimia.
- Excessive diarrhea, possibly from overuse of laxatives.
- Excessive sweating due to working out, illness, or medication use.
- Excessive vomiting.
- Genetic disorders such as Bartter syndrome or Gitelman syndrome. (Both are rare disorders.)
- Inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis.
- Low magnesium levels in the blood.
- Medications that cause too much potassium to move from the blood into cells. These drugs include insulin and asthma drugs like albuterol and terbutaline.
- Medications that cause you to lose too much potassium in your urine, including diuretics (water pills).
- Overuse of certain antibiotics.
Complications of hypokalemia
Mild cases of hypokalemia usually do not cause serious complications.
However, if your potassium levels are very low and are left untreated, you may experience:
- Abnormal heart rhythms that could be life-threatening.
- Fainting or lightheadedness.
- High blood pressure.
- Low blood pressure.
- Paralysis, in severe and rare cases.
How can I prevent hypokalemia?
Hypokalemia isn’t always preventable. However, taking medications exactly as prescribed, avoiding excessive sweating, and eating a healthy diet that includes potassium-rich fruits and vegetables may help.
Potassium-rich foods include:
- Avocados
- Bananas
- Beans
- Carrots
- Dates
- Milk
- Nectarines
- Oranges
- Peanut butter
- Pork loin
- Potatoes
- Seafood
- Spinach
- Tomatoes
How common is hypokalemia?
Severe hypokalemia is rare in healthy people. However, it can occur in people who have had a severe illness, sweat excessively, are hospitalized, or who take medications for kidney disease.
Mild cases are sometimes found during routine blood testing.
What Are the Signs and Symptoms of Hypokalemia?
Mild cases of hypokalemia may not cause noticeable symptoms. If you do have symptoms, they can be similar to other problems.
Mild low potassium symptoms include:
- Constipation.
- Feeling tired.
- Muscle weakness.
- Numbness or tingling in your hands or feet.
More severe cases may cause:
- Abnormal heart rhythm.
- Bloating and constipation.
- Fainting.
- Fatigue.
- Frequent urination.
- High blood pressure.
- Lightheadedness.
- Low blood pressure.
- Muscle cramps or weakness.
- Numbness and tingling, usually in your hands, arms, feet, and legs.
How does low potassium make you feel?
If you have low potassium, you may feel weak, tired, or have muscle cramps. You may also experience lightheadedness, numbness, or urinate more than usual.
When should I see a doctor about my hypokalemia symptoms?
If you have symptoms of hypokalemia, you should schedule an appointment with your medical provider as soon as possible. If you have severe symptoms — such as heart palpitations or fainting — go to your nearest hospital emergency department.
How Do You Diagnose Hypokalemia?
Hypokalemia is usually diagnosed with a blood test to check your potassium level.
What to expect during your visit
During your visit, your doctor will:
- Ask about any medications you’ve taken recently.
- Order blood tests.
- Perform a physical exam.
- Review your health history.
Tests to diagnose hypokalemia
Blood tests
If your doctor suspects you have low potassium, they’ll order a potassium blood test.
The normal range or safe zone for high or low potassium is 3.5 to 5 millimoles per liter (mmol/L). The caution zone is 2.5 to 3.4 mmol/L for low potassium. If your reading is lower than 2.5 mmol/L, you’re in the danger zone for low potassium.
The potassium blood test is usually part of an electrolyte panel. This is a group of routine blood tests that measure the amount of electrolytes in your body.
Because other hormones and minerals can affect your potassium level, your doctor may also order other blood tests to check your levels of:
- Glucose.
- Hormones produced by the thyroid and adrenal glands.
- Minerals such as magnesium, calcium, sodium, or phosphorus.
Other tests
Your doctor may also order a urine test to determine your potassium levels. They typically order urine tests if the cause of low potassium isn’t clear. That might be the case if you're not vomiting or using diuretics or other drugs.
Your doctor may order a test called an electrocardiogram (ECG or EKG) to check for abnormal heart rhythms. An EKG is a simple and fast outpatient diagnostic procedure used to evaluate your heart's electrical system.
Hypokalemia prognosis
With medical treatment and ongoing monitoring, most people can recover from or manage hypokalemia.
If your hypokalemia is mild and caused by a temporary health issue, you may only need treatment for a few days or weeks. If your hypokalemia is severe and due to a chronic condition, such as kidney disease or long-term medication use, you may need ongoing treatment.
How Do You Treat Hypokalemia?
Most cases of hypokalemia need to treatment from a medical provider. Adding more potassium to your diet is usually not enough to treat hypokalemia.
Although over-the-counter potassium supplements are available, self-treatment can be dangerous due to the potential for overdose.
Your doctor may recommend:
Lifestyle changes
Although increasing potassium levels in your diet is usually insufficient to treat hypokalemia after it develops, it may help prevent future recurrences. Your doctor or a registered dietitian can recommend potassium-rich foods to raise your potassium levels safely.
Medication changes
If your provider suspects that your diuretic medication caused you to develop hypokalemia, they may switch you to a different type of diuretic. “Potassium-sparing” diuretics may reduce the risk of hypokalemia.
Oral potassium supplements to treat hypokalemia
Mild hypokalemia is usually treated with oral potassium supplements. Your provider will let you know how and when to take potassium supplements safely and will monitor your potassium levels to ensure they are within the recommended range.
Intravenous (IV) potassium to treat hypokalemia
If you have severe hypokalemia, you may need to get intravenous potassium. You may need to stay in the hospital while you receive IV potassium therapy so your provider can monitor your levels and reduce the risk of related complications.
Is hypokalemia treatment right for me?
If you have symptoms of hypokalemia, you should seek medical treatment. Treatment can help prevent severe, life-threatening complications.
How long does it take to recover from treatment for hypokalemia?
Your recovery time depends on the severity of your condition and what treatment you need.
Treatment for milder cases can be as short as a few days or weeks. If you develop life-threatening complications like a heart arrhythmia, you may need ongoing medical care.
Why Choose UPMC for Hypokalemia Care?
When you choose UPMC for hypokalemia care, you will receive:
- Access to world-class nephrology expertise — Our world-renowned experts treat the full spectrum of kidney and related diseases using the latest techniques for diagnosis and treatment.
- Advanced diagnostic care —We’ll find the cause of your illness and work with you to develop a comprehensive treatment plan.
- A full range of treatment options — We offer comprehensive care tailored to your individual needs.
