Although most people in the Western world don't consume as much potassium as they should, healthy adult blood potassium levels are rarely low enough to cause symptoms of low potassium, or hypokalemia.
Symptoms of Hypokalemia
Hypokalemia can cause a variety of symptoms, including muscle weakness or cramping, fatigue, constipation, abdominal pain, and a change in the normal rhythm of the heart. Because of potassium's important role in regulating heart function, severe hypokalemia can be life threatening.
Causes of Hypokalemia
Most cases of hypokalemia are caused by conditions that either prevent the body from properly absorbing dietary potassium or cause it to excrete too much potassium. While hypokalemia in the Western world is very rarely caused by inadequate dietary consumption of potassium, exceptions include chronic alcoholics who ignore food in favor of alcohol, anorexics, terminal cancer patients, and the elderly. Hypokalemia due to improper absorption of dietary potassium can occur due to any illness or behavior that causes frequent vomiting or diarrhea. Malabsorption illnesses such as Crohn's disease can also lead to hypokalemia. Hypokalemia caused by excessive excretion of potassium can be caused by impaired kidney function, excessive use of diuretics, and either primary or secondary hyperaldosteronism. Rarely, consumption of large amounts of black licorice can cause hypokalemai, as black licorice contains a compound that increases urinary excretion of potassium. Some medications can also affect potassium levels.
How Hypokalemia Is Diagnosed
A blood test is necessary to diagnose hypokalemia. Normal blood potassium levels are between 3.6 to 4.8 milliequivalents per liter (mEq/L). When levels drop below 2.5 mEq/L, it's considered a life threatening condition that requires immediate medical treatment. Once hypokalemia is diagnosed, it's useful to test urine potassium levels to differentiate hypokalemia caused by malabsorption or inadequate potassium intake from hypokalemia caused by excessive urinary excretion of potassium. The patient should also be tested for hyperaldosteronism.
Treatments for Hypokalemia
Potassium replacement therapy in a hospital setting is necessary for patients with severe hypokalemia. Patients with mild to moderate hypokalemia can be treated with potassium supplementation on an outpatient basis as long as they don't have any cardiac issues and aren't on digoxin.
Time for the Doctor
Because hypokalemia can develop into a life-threatening condition, it's important to seek immediate medical treatment if you experience any of the symptoms of hypokalemia and have any reason to suspect that you may be suffering from low potassium levels.