Hyponatremia (cont.)

Medical Author:
Medical Editor:

What are the symptoms of hyponatremia (low blood sodium)?

When sodium levels in the body are low, water tends to enter cells, causing them to swell. When this occurs in the brain, it is referred to as cerebral edema. Cerebral edema is particularly dangerous because the brain is confined in the skull without room for expansion, and the swelling can lead to brain damage as the pressure increases within the skull. Cerebral edema is only a danger in severe cases of hyponatremia.

In chronic hyponatremia, in which the blood sodium levels drop gradually over time, symptoms are typically less severe than with acute hyponatremia (a sudden drop in blood sodium level). Symptoms can be very nonspecific and can include:

  • headache,
  • confusion or altered mental state,
  • seizures, and
  • decreased consciousness which can proceed to coma and death.

Other possible symptoms include:

Nausea and vomiting may accompany any of the symptoms.

How is hyponatremia (low blood sodium) diagnosed?

The symptoms of hyponatremia are nonspecific, so a blood test measuring the sodium level is required to confirm the diagnosis of hyponatremia. Sometimes the medical history (such as prolonged vomiting or excessive sweating) will suggest the diagnosis. In other cases, further blood tests, urine tests, and imaging studies may be needed in order to determine the exact cause of the hyponatremia.

Medically Reviewed by a Doctor on 12/4/2013

Patient Comments

Viewers share their comments

Hyponatremia - Experience Question: Please describe your experience with Hyponatremia.
Hyponatremia (Low Blood Sodium) - Symptoms Question: What are the symptoms associated with your hyponatremia?
Hyponatremia (Low Blood Sodium) - Diagnosis Question: What tests or exams led to a diagnosis of low blood sodium?
Hyponatremia (Low Blood Sodium) - Treatment Question: What kinds of treatment have you received for your low blood sodium?