A high level of sodium in the blood may indicate that an individual has diabetes insipidus, dietary sodium bicarbonate overdose or adrenal gland disorders such as hyperaldosteronism, according to MedlinePlus. It may also be an indicator of fluid loss as a result of conditions such as diarrhea and sweating.
Sodium is a necessary substance for normal body functions, notes MedlinePlus. The normal blood sodium level in 1 liter of blood ranges from 135 to 145 milliequivalents. A condition in which the blood sodium is higher than the normal level is known as hypernatremia.
The level of sodium in the body is determined through a blood test or a urine test, says MedlinePlus. Doctors recommend a sodium test on individuals who consume abnormal amounts of salt or fluids, those who have undergone surgical operations recently and those who recently suffered from a severe illness. Before the test, a doctor advises the patient not to take medications such as antibiotics, estrogen, hypertension drugs, diuretics and lithium, as these may lead to inaccurate test results.
To perform a sodium blood test, the doctor draws blood from a vein with a needle and takes the blood to the lab for analysis, states MedlinePlus. Though often safe, the procedure may cause lightheadedness, excessive bleeding and infection due to skin breakage.