Electrolytes are electrically charged molecules that serve various functions in the body. Some common electrolytes, such as potassium, sodium and calcium, play important roles in nerve conduction, muscle contraction and heart rhythm. Electrolyte levels are also important in maintenance of the body’s fluid balance. Several conditions can cause electrolyte imbalances.
The kidneys are the organs most involved in the maintenance of proper fluid and electrolyte balance. According to "The Merck Manual of Medical Information," the kidneys filter electrolytes from the blood, excreting excess levels of these molecules and reabsorbing others that are needed. The kidneys also excrete any excess fluid. Kidney damage, which can be caused by infection, inflammation or trauma, prevents these organs from maintaining the proper electrolyte concentration in the blood. This can cause serious medical problems, with either too high or too low electrolyte levels.
Dehydration can affect electrolyte levels. Sodium level, in particular, can be adversely affected. Gastroenteritis, or the stomach flu, can lead to dehydration and hyponatremia, or low sodium levels in the blood, when the body loses too much of this electrolyte during illness. Decreased intake of fluids can lead to dehydration and high sodium levels, as the concentration of this electrolyte increases in the absence of water. Dehydration due to heat exposure and high temperatures can decrease the levels of electrolytes, which are lost through sweat.
The adrenals, a pair of triangle-shaped glands located atop each kidney, secrete hormones involved in the body’s stress response, sexual development and fluid balance. The main adrenal hormone involved in electrolyte balance is aldosterone. According to Lab Tests Online, aldosterone stimulates the kidneys to retain sodium and excrete potassium. High levels of aldosterone can result in elevated levels of sodium and increased loss of potassium in the urine. Conditions like Addison’s disease, which causes underproduction of aldosterone, can result in low sodium and high potassium levels.
Certain medicines can affect electrolyte levels. Diuretics, used to control high blood pressure, work by increasing the excretion of sodium and water in the urine. According to MayoClinic.com, some diuretics can also decrease the level of potassium in the bloodstream. This can cause constipation, muscle cramps, weakness and abnormal heart rhythms, or arrhythmias. Other medicines, such as cough medicines, oral contraceptives and steroids, can affect sodium levels. Taking large amounts of certain antacids can affect chloride levels.