Hyponatremia (low blood sodium)

General or Other | Endocrinology and Metabolism | Hyponatremia (low blood sodium) (Disease)


Hyponatremia is a metabolic condition in which there is not enough sodium (salt) in the body fluids outside the cells.

Causes and Risk factors

Sodium is found mostly in the body fluids outside the cells. It is very important for maintaining blood pressure. Sodium is also needed for nerves and muscles to work properly.

When the amount of sodium in fluids outside cells drops, water moves into the cells to balance the levels. This causes the cells to swell with too much water. Although most cells can handle this swelling, brain cells cannot, because the skull bones confine them. Brain swelling causes most of the symptoms of hyponatremia.

In hyponatremia, the imbalance of water to salt is caused by one of three conditions: euvolemic hyponatremia -- total body water increases, but the bodys sodium content stays the same; hypervolemic hyponatremia -- both sodium and water content in the body increase, but the water gain is greater; hypovolemic hyponatremia -- water and sodium are both lost from the body, but the sodium loss is greater.

Diagnosis and Treatment

The health care provider will perform a complete physical examination to help determine the cause of your symptoms. Blood and urine tests will be done. The following laboratory tests can confirm hyponatremia: comprehensive metabolic panel (includes blood sodium), osmolality blood test, urine osmolality, urine sodium

The cause of hyponatremia must be diagnosed and treated. In some cases, cancer may cause the condition, and radiation, chemotherapy, or surgery to remove the tumor may correct the sodium imbalance. Other treatments depend on the specific type of hyponatremia. Treatments may include: fluids through a vein (IV), medication to relieve symptoms, water restriction. ...