The causes of low sodium levels include drinking too much water; disorders of the heart, liver or kidney; and certain medications such as diuretics, according to the Mayo Clinic. Conditions that cause chronic vomiting can also lead to low potassium levels.
Other causes of low potassium levels in the blood are a complication of diabetes called ketoacidosis, diarrhea, and heavy use of alcohol and laxatives. Other reasons are a deficiency of folic acid, diuretics use and chronic kidney disease. Low salt levels are called hyponatremia, while low potassium levels are called hypokalemia, according to the Mayo Clinic.
Another cause of low potassium levels is primary aldosteronism, says MedlinePlus. This disease comes about when the adrenal glands secrete too much of a hormone called aldosterone. In primary aldosteronism, the trouble begins in the adrenal glands. In most cases, a benign tumor causes the adrenal gland to malfunction.
Low sodium levels can also be due to fluctuations in hormone levels, according to Mayo Clinic. Addison's disease can disrupt the balance of not only salt but also potassium and water. The thyroid gland producing inadequate thyroid hormone can also cause hyponatremia. The recreational drug ecstasy, which is an amphetamine, can cause salt levels to become dangerously low.