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 3.5 to 5.5 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.
If you have hypokalemia, that means you have low levels of potassium in your blood. Potassium is a mineral your body needs to work normally. It helps muscles to move, cells to get the nutrients they need, and nerves to send their signals. It’s especially important for cells in your heart. It also helps keep your blood pressure from getting too high.
There are many different reasons you could have low potassium levels. It may be because too much potassium is leaving through your digestive tract. It’s usually a symptom of another problem. Most commonly, you get hypokalemia when:
Low potassium (hypokalemia) has many causes. The most common cause is excessive potassium loss in urine due to prescription medications that increase urination. Also known as water pills or diuretics, these types of medications are often prescribed for people who have high blood pressure or heart disease.
Vomiting, diarrhea or both also can result in excessive potassium loss from the digestive tract. Occasionally, low potassium is caused by not getting enough potassium in your diet.
Causes of potassium loss include:
It’s possible, but rare, to get hypokalemia from having too little potassium in your diet. Other things sometimes cause it, these are not limited to:
- Alcohol use (excessive)
- Chronic kidney disease
- Diabetic ketoacidosis
- Diarrhea
- Diuretics (water retention relievers)
- Excessive laxative use
- Excessive sweating
- Folic acid deficiency
- Primary aldosterone’s
- Some antibiotic use
- Vomiting
Women tend to get hypokalemia more often than men. If your problem is temporary, or you’re only slightly hypokalemic, you might not feel any symptoms. Low potassium symptoms may include:
- Weakness
- Fatigue
- Muscle cramps
- Constipation
- Abnormal heart rhythms (arrhythmias) are the most worrisome complication of very low potassium levels, particularly in people with underlying heart disease.
Talk to your doctor about what your blood test results mean. You may need to change a medication that’s affecting your potassium level, or you may need to treat another medical condition that’s causing your low potassium level.
Treatment of low potassium is directed at the underlying cause and may include potassium supplements. Don’t start taking potassium supplements without talking to your doctor first.
