Mayo Clinic Health Library


Low blood sodium in older adults: A concern?

Why is low blood sodium (hyponatremia) a health concern for older adults? How is it treated?

Updated: 08-19-2011


Low blood sodium (hyponatremia) occurs when you have an abnormally low amount of sodium in your blood, or when you have too much water in your blood. Low blood sodium is common in older adults, especially those who are hospitalized or living in long-term care facilities.

Older adults usually become ill with hyponatremia due to age-related causes that affect the way the body handles the balance of sodium and water, such as:

  • Taking certain medications, such as diuretics, antidepressants and pain medications
  • Changes in kidney function, such as decreased kidney size or decreased blood flow through the kidneys
  • Severe vomiting or diarrhea
  • Liver failure (cirrhosis)
  • Kidney failure
  • Heart failure
  • Having high levels of anti-diuretic hormone, which causes you to retain water
  • Drinking too much water
  • Urinating less frequently
  • Underactive thyroid (hypothyroidism)
  • Addison's disease, a condition affecting the adrenal gland

The signs and symptoms of hyponatremia vary. The only way a doctor can confirm whether you have hyponatremia is by a blood test. Signs and symptoms of hyponatremia may include:

  • Drowsiness or fatigue
  • Nausea
  • Headache
  • Confusion
  • Restlessness
  • Loss of consciousness or coma

Hyponatremia treatments may include changing a medication that affects your sodium level, changing the amount of water you drink, or changing the amount of salt in your diet.