What we know as salt is really sodium chloride. It is 40 percent sodium and the rest is chlorine.

The human body regulates how much sodium it contains. If levels are too high, we get thirsty and drink, and the kidneys speed up the process of getting rid of it.

Too much sodium has been linked to kidney stones, high blood pressure and cardiovascular disease.

Too little sodium can lead to hyponatremia, symptoms of dizziness, confusion, muscle twitches and seizures.