Why can we not drink sea water?

+85 votes
asked Mar 27, 2015 in Science by leatrice (1,190 points)
I've told that people will dehydrate in the sea without enough drink water. But I don't understand this. The difference between water and sea water is a little salt. We also eat salt every day. Why does this little salt make the water not drinkable for people?

3 Answers

+23 votes
answered Mar 30, 2015 by Phillip (1,040 points)

The answer is quite simple: Seawater contains too much salt for human consumption. Although we can consume salt in small amounts, our bodies cannot handle taking in as much salt as is contained in seawater. Drinking seawater would have horrible consequences, including severe dehydration and even death. Our bodies need a certain amount of salt to function. We take in salt but we also drink much through the day which dilutes the salt. Without this dilution, dehydration is inevitable.

When you drink liquids, your body rids itself of anything it doesn’t need by making you urinate. If you drink seawater, the same would occur, only the salt would remain. This would cause severe dehydration, and even possibly death. Your kidneys would try to process the salt water but would struggle doing so.

REFERENCE: http://science.howstuffworks.com/science-vs-myth/what-if/what-if-you-drink-saltwater.htm

+5 votes
answered Apr 3, 2015 by Xoshia (700 points)
Drinking seawater would allow too much salt into your blood stream. This can be deadly! Your kidneys cannot remove all that salt without extra hydration. You’d have to drink a whole lot of fresh water to dilute all the salt in seawater!

The reason other mammals and birds can handle drinking seawater is that their bodies have evolved to have kidneys that can handle the processing of all that salt.
+3 votes
answered Mar 31, 2015 by Phuong (570 points)
Why can we not drink sea water? This is because your kidneys can’t handle it! If you drink seawater, you’ll just get thirstier because your kidneys aren’t made to process that much salt! If you are thirsty even more and drink even more salt water, eventually you’ll get dehydrated and die.
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