人可以喝海水吗？
Seawater contains salt, so when people drink it, their cells take in both water and salt. Our bodies can safely handle small amounts of salt, but seawater contains far more salt than the human body can process.
When we eat salty food as part of our normal diet, we also drink liquids, which dilute the salt and keep it at a healthy level. Living cells do need sodium chloride, or salt, to keep the body's chemistry in balance. However, too much sodium can be deadly.
The problem is the kidneys. Human kidneys can only make urine that is less salty than seawater. So to get rid of all the extra salt from drinking seawater, you would have to pass more water than you drank. In the end, you would die of dehydration, even as you became thirstier and thirstier.
海水里含有盐，所以人喝海水时，身体的细胞会同时吸收水和盐。人体能安全地处理少量的盐，但海水里的盐远远超过了人体能够处理的量。
我们平时吃咸的食物时，也会喝水或其他饮料，把盐稀释，让体内的盐分保持在健康的水平。活细胞确实需要氯化钠，也就是盐，来维持身体的化学平衡。可是钠太多了，是会要人命的。
问题出在肾脏上。人的肾脏只能排出比海水淡的尿液。所以，要把喝海水摄入的多余盐分全部排出去，排出的水就得比喝进去的还多。到最后，人会越喝越渴，最终因为脱水而死。