Hypernatremia

Rapid intake of large amounts of sodium (e.g., drinking seawater) can cause the retention of sodium and water in the blood.

Hypernatremia usually results from dehydration. If the thirst mechanism is defective, whether through natural causes or because the patient cannot get on water even though he or she is thirsty, homeostasis is altered.

This cause hypernatremia, abnormally high concentration of sodium in the blood and hypervolemia, an abnormal increase in blood volume.

This leads to edema (swelling) and a rise in blood pressure.

A healthy person with normal kidneys and ample water intake rapidly excretes sodium, so hypernatremia usually is seen only in patients with congestive heart failure or kidney disease.

Patient with hypernatremia may be asymptomatic, or they may present with seizures, altered mental status or coma.

Eating too much sodium over a long period of time can contribute to high pressure (hypertension) in some people.

For those with high blood reassure, lowering sodium intake is a useful dietary change that may lower blood pressure.

Excess dietary sodium can also contribute to osteoporosis by increasing calcium loss in the urine.

Other situations associated with or causing hypernatremia include nephrogenic diabetes insipidus when the kidney fails to respond to vasopressin, in diuretic therapy, or by salt poisoning.

Central diabetes insipidus due to failure of the hypothalamus to make vasopressin may occur as a consequence or cerebrovascular disease ischemia and head trauma, resulting in hypernatremia.

Hypernatremia is a serum sodium level greater than 145 mEq/L. It is classified into hypovolemic hypernatremia, isovolemic hypernatremia, and hypervolemic hypernatremia.

Hypernatremia occurs in about one to three percent of elderly persons and in 0.3 to 1 percent of hospitalized patients.
Hypernatremia