Question: Why is it really bad for you to drink sea water if we practically sweat and cry sea water?

Josh Meyers answered on 16 Jun 2015:

This is because the salt content of seawater is too high.

The body needs water to function. Human kidneys use some of this water to dissolve and remove salt from our body. To get rid of all the excess salt taken in by drinking seawater, you have to urinate more water than you drank. Eventually, you die of dehydration.