Hyponatremia is a condition in which the amount of sodium (salt) in the blood is lower than normal.
Dilutional hyponatremia; Euvolemic hyponatremia; Hypervolemic hyponatremia; Hypovolemic hyponatremia
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, muscles, and other body tissues 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. Brain cells are especially sensitive to swelling, and this causes many of the symptoms of hyponatremia.
- Euvolemic hyponatremia — total body water increases, but the body’s 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
Hyponatremia can be caused by:
Burnsthat affect a large area of the body
- Diuretic medicines, which increase urine output
- Kidney diseases
cirrhosis Syndrome of inappropriate antidiuretic hormone secretion(SIADH)
Common symptoms include:
Confusion Convulsions Fatigue
Loss of appetite Muscle spasmsor cramps Muscle weakness
Exams and Tests
The health care provider will perform a complete
The following laboratory tests can confirm and help diagnose hyponatremia:
Comprehensive metabolic panel(includes blood sodium) Osmolalityblood test Urine osmolality Urine sodium
The cause of hyponatremia must be diagnosed and treated. If cancer is the cause of the condition, radiation,
Other treatments depend on the specific type of hyponatremia.
Treatments may include:
Fluids through a vein (IV)
Medication to relieve symptoms
The outcome depends on the condition that is causing the problem. Acute hyponatremia, which occurs in less than 48 hours, is more dangerous than hyponatremia that develops slowly over time. When sodium level falls slowly over days or weeks (chronic hyponatremia), the brain cells have time to adjust and swelling is minimal.
In severe cases, hyponatremia can lead to:
- Decreased consciousness, hallucinations or coma
When to Contact a Medical Professional
Hyponatremia can be a life-threatening emergency. Call your health care provider right away if you have symptoms of this condition.
Treating the condition that is causing hyponatremia can help. If you play sports, drink fluids such as sports drinks that contain electrolytes. Drinking only water while you are active can lead to acute hyponatremia.