Low potassium (hypokalemia) refers to a lower than normal potassium level in your bloodstream. Potassium helps carry electrical signals to cells in your body. It is critical to the proper functioning of nerve and muscles cells, particularly heart muscle cells.
Normally, your blood potassium level is 3.6 to 5.2 millimoles per liter (mmol/L). A very low potassium level (less than 2.5 mmol/L) can be life-threatening and requires urgent medical attention.
What is hyperkalemia (high potassium)?
Hyperkalemia occurs when potassium levels in your blood get too high. Potassium is an essential nutrient found in foods. This nutrient helps your nerves and muscles function. But too much potassium in your blood can damage your heart and cause a heart attack. You can’t always tell when your potassium levels are high.
What is a safe or normal potassium level?
A typical potassium level for an adult falls between 3.5 and 5.0 millimoles per liter (mmol/L). Hyperkalemia occurs when levels go above 5.5 mmol/L. A reading above 6.5 mmol/L can cause heart problems that require immediate medical attention.
Who might have hyperkalemia (high potassium)?
Anyone can get hyperkalemia, even children. You may be more at risk if you have:
- Addison’s disease.
- Alcohol use disorder (alcoholism).
- Burns over a large part of your body.
- Congestive heart failure.
- Human immunodeficiency virus (HIV).
- Kidney disease.
SYMPTOMS AND CAUSES
What causes hyperkalemia (high potassium)?
Your kidneys filter potassium from the foods and drinks you consume. Your body gets rid of excess potassium when you pee. With hyperkalemia, your body has too much potassium for your kidneys to remove. As a result, potassium builds up in your blood.
In addition to conditions like kidney disease, these factors also contribute to hyperkalemia:
- A high-potassium diet, which can result from potassium supplements and salt substitutes.
- Medications that contain potassium, such as certain high blood pressure medicines.
What are the symptoms of hyperkalemia (high potassium)?
Many people with mild hyperkalemia have no signs or ones that are easy to dismiss. Symptoms often come and go and may come on gradually over weeks or months. Dangerously high potassium levels affect the heart and cause a sudden onset of life-threatening problems. Hyperkalemia symptoms include:
- 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.
DIAGNOSIS AND TESTS
How is hyperkalemia (high potassium) diagnosed?
Because most people don’t have symptoms, you might not know you have high potassium until you get a routine blood test. A serum potassium test measures potassium levels in blood. Your healthcare provider may also order an electrocardiogram (EKG). This test shows changes in heart rhythm caused by hyperkalemia.
MANAGEMENT AND TREATMENT
What are the complications of hyperkalemia (high potassium)?
Severe hyperkalemia can come on suddenly. It can cause life-threatening heart rhythm changes (arrhythmia) that cause a heart attack. Even mild hyperkalemia can damage your heart over time if you don’t get treatment.
How is hyperkalemia (high potassium) managed or treated?
Treatment varies depending on the potassium level. Options include:
- Diuretics: Also called water pills, these drugs make you pee more often. Your body gets rid of potassium mainly in urine.
- Intravenous (IV) therapy: Extremely high potassium levels need immediate treatment. You’ll receive an IV infusion of calcium to protect your heart. Next, you get an infusion of insulin that helps move potassium into the blood cells. You may also inhale an asthma medication called albuterol to further lower potassium levels.
- Medication management: Many people see improvement after stopping or changing certain blood pressure medications or other drugs that raise potassium levels. Your healthcare provider can determine what medication changes to make.
- Potassium binders: A daily medication binds to excess potassium in the intestines. You pass the potassium when you poop. Your provider may recommend binders if other treatments don’t lower potassium levels. Potassium binders come in oral and enema form.
- Dialysis: If potassium levels remain high, or you experience kidney failure, you may need dialysis. This treatment helps your kidneys remove excess potassium from blood.
How can I prevent hyperkalemia (high potassium)?
If you’ve had hyperkalemia or are at risk for it, a low-potassium diet is the best way to protect your health. You may need to cut back on, or completely cut out, certain high-potassium foods, such as:
- Citrus fruits and juices, such as oranges and grapefruit.
- Cooked spinach.
- Melons like honeydew and cantaloupe.
- Prunes, raisins and other dried fruits.
- Pumpkin and winter squash.
- Salt substitutes that contain potassium.
- Tomatoes and tomato-based products like sauces and ketchup.
OUTLOOK / PROGNOSIS
What is the prognosis (outlook) for people who have hyperkalemia (high potassium)?
Changes to your diet and medication often resolve mild cases of hyperkalemia. With the right care, most people don’t have long-term complications from hyperkalemia. Your healthcare provider may order more frequent blood tests to ensure your potassium levels stay within a healthy range.
When should I call the doctor?
You should call your healthcare provider if you experience:
- Difficulty breathing.
- Extreme muscle weakness or fatigue.
- Severe abdominal pain, vomiting or diarrhea.
- Weak pulse, chest pain or signs of a heart attack.
What questions should I ask my doctor?
If you have hyperkalemia (high potassium), you may want to ask your healthcare provider:
- Why did I get hyperkalemia?
- How often should I get blood tests to check for hyperkalemia?
- How much potassium should I get in my daily diet?
- What foods or supplements should I avoid?
- What, if any, salt substitutes can I use?
- What are the treatment risks and side effects?
- Am I at risk for kidney failure or other problems due to hyperkalemia?
- What follow-up care do I need after treatment?
- Should I look out for signs of complications?
A note from Cleveland Clinic
Because hyperkalemia rarely causes symptoms, you may be surprised when a blood test shows that your potassium levels are high. A low-potassium diet can protect your health. Your healthcare provider can determine how much potassium you need or connect you with a dietitian, if needed. A dietitian can help you create meal plans that ensure you get just the right amount of potassium in your diet. Your provider may also change your medications. Potassium levels that reach a dangerously high level can be life-threatening. If you’re at risk for hyperkalemia, your provider will closely monitor your potassium levels.