A sodium blood test is a routine test that allows your doctor to see how much sodium is in your blood. Sodium is an essential mineral to your body.
A normal blood sodium level is between 135 and 145 milliequivalents per liter (mEq/L).
In hypernatremia, the level of sodium in blood is too high. Hypernatremia involves dehydration, which can have many causes, including not drinking enough fluids, diarrhea, kidney dysfunction, and diuretics.
Hyponatremia occurs when the sodium in your blood falls below 135 mEq/L. Symptoms include lethargy, confusion, and fatigue. It can result from underlying conditions, such as kidney failure, or other factors, such as drinking too much water or taking certain medications.