What does your body use to get rid of salt?

Your body uses water to get rid of excess salt. The kidneys filter the blood and transfer surplus sodium and chloride into urine, but water is needed to carry those dissolved salts out of the body.

This is why eating a very salty meal can make you thirsty. Extra sodium raises the concentration of dissolved particles in body fluids, and the brain signals you to drink. The added water helps the kidneys produce urine containing the excess salt.

The kidneys constantly adjust the balance between salt and water. They conserve water when you are dehydrated and make more dilute or more concentrated urine depending on what the body needs. Sweat also removes some salt, but urination is the main route for clearing dietary excess.

Seawater illustrates the limitation: it contains more salt than human kidneys can safely excrete in the available water, so eliminating that salt can cause a net loss of body water.