The most common cause of low potassium levels, also called hypokalemia, is when excessive potassium is lost through the urine due to the use of diuretics, according to Mayo Clinic. Diarrhea and vomiting can also cause potassium loss from the digestive tract.
Other causes of potassium loss leading to low potassium levels include chronic kidney disease, excessive sweating, folic acid deficiency and the use of some antibiotics, notes Mayo Clinic. Excessive use of alcohol or laxatives can also lead to potassium loss. Rarely is not getting enough potassium in one’s diet the cause of low potassium.
Diabetic ketoacidosis is another cause of potassium loss, states Mayo Clinic. A serious complication of diabetes, diabetic ketoacidosis occurs when the body is unable to produce enough insulin. The result is high levels of blood acids called ketones. Primary aldosteronism, a hormonal disorder that causes high blood pressure, is another cause of potassium loss. This disorder causes the adrenal glands to produce too much aldosterone, a hormone that balances potassium and sodium in the blood.
A normal blood potassium level is 3.6 to 5.2 millimoles per liter, explains Mayo Clinic. Less than 2.5 millimoles per liter is considered a very low potassium level and can be life-threatening. Potassium is essential for the proper functioning of nerve and muscle cells, especially the muscle cells of the heart.