Sodium in the blood normally stays within a narrow range, between 135 and 145 milliequivalents per liter, or mEq/L, MayoClinic.com reports. Sodium, an essential mineral, helps maintain blood pressure and aids in normal muscle and nerve function, according to the Milton S Hershey Medical Center. Sodium levels below 135 indicate hyponatremia, or low sodium levels. Many diseases and drugs can cause hyponatremia.
Diarrhea and Vomiting
Diarrhea and vomiting cause hypovolemic hyponatremia, a condition where both the total water volume and sodium levels fall below normal. In hypovolemia hyponatremia, the decrease in sodium is proportionately higher than the water loss, causing hypovolemic, or low water volume hyponatremia, the Merck Manual states.
Diuretics
Diuretics cause an increase in urination, which washes away an excess amount of sodium, the Milton S. Hershey Medical Center explains. Diuretics also result in increased fluid loss, causing hypovolemic hyponatremia. Elderly patients, who have increased sodium diuresis, especially when taking Thiazide diuretics, may develop severe, life-threatening hyponatremia within a few weeks of starting the drugs, the Merck Manual warns. Hyponatremia may last several weeks after discontinuing the drug.
Ecstasy
The recreational drug Ecstasy can cause dangerous hyponatremia, according to MayoClinic.com. Ecstasy causes hyponatremia by upsetting the body's anti-diuretic hormone and water levels and can lead to death, especially if combined with heavy drinking, which also acts as a diuretic.
Excess Water Intake
Increased water intake leads to euvolemic hyponatremia, also known as dilutional hyponatremia, where the amount of sodium is normal or near normal but the total water volume is greater than normal, the Merck Manual states. Some psychiatric conditions cause excessive water intake; strenuous exercising and diabetes can also cause extreme thirst and excessive water intake.
Hormone-Related Causes
Certain hormone related disease can cause low sodium levels and euvolemic hyponatremia. High levels of anti-diuretic hormone, which occur in Syndrome of Inappropriate Anti-diuretic Hormone, or SIADH, causes water retention that leads to excess fluid retention. Underactive thyroid can also lead to hyponatremia, MayoClinic.com warns.
Fluid Retention Diseases
Kidney disease and kidney failure may result in excess fluid retention, which leads to hypervolemic hyponatremia, where both fluid and sodium levels are higher than normal, but sodium levels are relatively higher, the Merck Manual explains. Cirrhosis of the liver, which can result in ascites, fluid retention that accumulates in the abdomen and congestive heart failure, which results in fluid retention in the lower extremities can both cause hypervolemic hyponatremia.
Member Comments