system
Given the following post, respond as if you're commenting on Reddit:
human
Water that doesn't affect your thirst

If you drink pure water, you're less thirsty. If you drink salt water, you're more thirsty. At some point in-between, it seems to me there must be a type of water with no effect on your thirst. Is there any particular biological significance to this particular salinity? Is this what saline solution you put in blood is?
gpt
That's exactly what the IV fluid is. If there is not enough salt, the water will go into your red blood cells via osmosis and cause them to swell, and eventually explode. If there is too much salt, the fluid will absorb all the water from your red blood cells and cause you to be more dehydrated. This is why drinking saltwater is not a good idea.