What Is a Serum Sodium Test

Serum sodium; Sodium – serum. The sodium blood test measures the concentration of sodium in the blood. Sodium can also be measured using a urine test. Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand.

What does serum sodium indicate?

Once your body takes in enough sodium, the kidneys get rid of the rest in your urine. If your sodium blood levels are too high or too low, it may mean that you have a problem with your kidneys, dehydration, or another medical condition.

What happens if serum sodium is high?

Hypernatremia typically causes thirst. The most serious symptoms of hypernatremia result from brain dysfunction. Severe hypernatremia can lead to confusion, muscle twitching, seizures, coma, and death.