What is the normal blood sodium level and why is it important to maintain within a certain range?

The normal blood sodium level is around 135-145 milliequivalents per liter (mEq/L). It is important to maintain sodium levels within this range because sodium plays a crucial role in regulating the balance of fluids in the body, nerve function, and muscle contractions. Abnormal sodium levels can lead to health issues such as dehydration, swelling, and neurological problems.