Sodium is an essential electrolyte that helps maintain the balance of water in and around your cells. It's important for proper muscle and nerve function. It also helps maintain stable blood pressure levels. Insufficient sodium in your blood is also known as hyponatremia.

The human body can't live without some sodium. It's needed to transmit nerve impulses, contract and relax muscle fibers (including those in the heart and blood vessels), and maintain a proper fluid balance.

A condition called hyponatremia, or low blood sodium levels, may affect certain people like older adults and some athletes. Eating less salt raises the risk of this condition.