Why can't we use sea water

Why can't we drink sea water?

We humans need to drink regularly. The body needs fluids. If we don't get anything, we die of thirst. But sea water is not suitable for survival. Experts know why.

The experts say: the sea water is salty and that is a problem for our body. The salt is dissolved in the water. There is about one tablespoon of salt per liter. When we drink this water, we do not quench our thirst. On the contrary: Not only that we feel sick. We die of thirst from within. But what is happening in our body?

The experts say that our body is largely made up of water. It is in the blood and in the cells, i.e. in the building blocks of the body. In addition to water, our body needs salt and minerals. The kidneys ensure that the body gets the salt from the body fluids. If there is too much salt it will be excreted. However, the kidneys can only cope with this task if they are given fresh water. You need water that has not yet dissolved anything. That is why we drink tap water or mineral water, for example.

When we drink sea water, the kidneys work at full speed. There is too much salt in the body and we need to get rid of it. The kidneys therefore draw water from other cells in order to deal with the high levels of salt in seawater. If we drink one liter of sea water, the kidneys need one and a half liters of other water to bring everything into balance. So we are withdrawing water from our body when we drink sea water. The experts say we die of thirst from within. Our thirst grows.

This can only be solved if we can get fresh water. In the films, for example, it's rainwater that falls from the sky. The castaways can then collect and drink it.