Hypernatremia is an elevated concentration of serum sodium, or sodium in the blood. It results from an inadequate intake of water and usually develops in patients who are physically or mentally impaired to the point that they are unable to access water, or even to request it. Normally, even a slight increase in the body's sodium level will create intense thirst, but if water is unavailable, or a patient is unable to communicate thirst, hypernatremia can result. Hypernatremia is most common in infants, mentally disabled patients, patients who are comatose, and the elderly, particularly those with dementia.
Causes of Hypernatremia
Hypernatremia may be caused by anything that interferes with the ratio of sodium to water in the body, such as:
- Diabetes insipidus
- Kidney dysfunction
- Extreme environmental conditions in which drinking water is unavailable
- Excessive sweating
- Rare diseases in which the thirst impulse is impaired
- Impaired kidney function
- Malfunction of the hypothalamus or pituitary gland
- Accidental sodium overdose
Symptoms of Hypernatremia
Symptoms of hypernatremia may appear suddenly as the brain cells are unable to adapt to changing levels of sodium in the blood. Hypernatremia should be suspected when a patient shows signs of the following:
- Edema, or swelling
- Lack of coordination
- Muscle cramps
- Blood pressure fluctuations
In more advanced stages, a patient with hypernatremia may suffer brain injury evidenced by seizures or loss of consciousness.
Diagnosis of Hypernatremia
Since a patient with hypernatremia may be in a weakened state to begin with, the condition is not always easy to diagnose. In order to diagnose hypernatremia, the physician will take a blood sample in order to evaluate the concentration of sodium in the blood and perform diagnostic tests to determine urine output.
Treatment of Hypernatremia
Hypernatremia has to be treated carefully and gradually to avoid complicating the condition. It is important to maintain the balance of electrolytes in the body. Usually, an infusion of a sodium chloride solution, natural to the blood, is administered over a period of days to bring the patient's serum sodium content back to a normal level. In an emergency, when the patient is already experiencing neurological symptoms, the infusion administered may be more dilute, containing only half the normal serum sodium level.
Risks of Hypernatremia
Hypernatremia is a serious condition which, in severe cases, can lead to brain injury, seizures, coma or death.
Recovery from Hypernatremia
In spite of the dangerous nature of hypernatremia, cases which are treated appropriately are usually easily cured. Patients recovering from hypernatremia are strongly advised to hydrate themselves carefully, particularly during exercise, and to have their blood sodium levels checked frequently. Once the condition has advanced, hypernatremia is associated with a high mortality rate.