Hypokalemia is a potentially life-threatening condition caused when potassium falls to lower-than-normal levels. The technical definition is having a serum potassium concentration below 3.5 mmol/L. Although there can be many causes of low potassium, Maureen Brogan, MD and nephrologist at Westchester Medical Center in Valhalla, New York says that hypokalemia is most commonly a result of urine loss resulting from taking diuretics. Since older patients are more likely to take water pills to treat hypertension or heart disease, this is the population who is most at risk.
Causes of Hypokalemia Among Older Adults
Though diuretics are the most common cause of hypokalemia, potassium can also be lost from the body through urine, stool or sweat, notes Malena Law, MD and board certified internist in Santa Monica, California. It’s rare for someone to have hypokalemia because they’re not getting enough potassium in their diet.
Excessive vomiting or diarrhea, weight loss surgery, excessive alcohol consumption and folic acid deficiency are additional culprits. Experts agree that anyone with prolonged vomiting or diarrhea (persisting for more than 24 to 48 hours) should seek medical attention since the loss of fluids increases the odds of losing too much potassium. Some common antibiotics (such as Ampicillin and Penicillin), medicines to treat chronic obstructive pulmonary disease (such as Albuterol and Ephedrine), and even foods like black licorice (if you overdo it) can lower your potassium levels; so can gastrointestinal infections, chronic kidney disease and chemotherapy.
Why Your Body Needs Potassium
Potassium is critical for normal cell function. “This electrolyte is very unique,” explains internist Peter Galier, MD and vice chief of staff at UCLA Medical Center, Santa Monica. “Every muscle in your body needs potassium to function properly.” Potassium works with sodium to keep your blood pressure normal; it also helps your body maintain a healthy balance of fluids and aids in the transmission of electrical pulses to help your nerves and muscles function.
Signs and Symptoms of Hypokalemia
A small drop in potassium levels could cause symptoms so mild — such as fatigue, muscle weakness or spasms or constipation — that you might shrug them off as common, everyday occurrences. In a lot of cases, “it’s possible to have hypokalemia and not even realize it,” says Dr. Galier. Typically, hypokalemia is only detected “by accident“ — like when checking for something else entirely. For example, you might go to the Emergency Room for a cough or fever, and a routine metabolic (blood) panel turns up the findings. Other times, it’s detected by routine blood tests for people who take diuretics.
But as potassium levels drop lower, Dr. Galier notes that people may experience hypokalemia’s not-so-subtle signs such as severe muscle cramping or abnormal heart rhythms, or other heart disturbances like tachycardia and ventricular fibrillation, which are the most concerning complication of very low potassium levels. Changes can be seen on an electrocardiogram (ECG); and while hypokalemia can cause serious cardiac complications, they’re usually correctable if a diagnosis is made.
How to Treat Hypokalemia
Treatment for hypokalemia varies, and many times it depends on its severity and its causes. It may be as simple as supplementing your diet with daily doses of potassium-rich foods, such as bananas, avocados, potatoes, spinach, kiwi, dried fruits or nuts. Another option might be to change the medication that’s affecting your potassium levels. If it’s caused by your diuretic, ask your doctor about switching to a potassium-sparing diuretic.
Milder hypokalemia might also be treated with oral potassium supplements (Dr. Galier suggests taking the pills with meals, since they can cause stomach irritation), which can usually correct the problem. More severe conditions of hypokalemia might require potassium to be given intravenously.
