system
Given the following post, respond as if you're commenting on Reddit:
human
What happens to a person dying of thirst if they drink seawater?

If a person is dying of thirst on a raft adrift in the sea, they'll likely be tempted to drink seawater even though they know it won't help.

What will happen to the person once they consume some seawater?

I know they will eventually die, but I'm curious as to how. Specifically, what happens biologically and psychologically?

Biologically: What happens to the body.

Psychologically: Do they still feel thirsty? Do they feel any pain?
gpt
Our bodies maintain a very narrow range in concentration of sodium and chloride inside (intracellular space) and outside (interstitial space) cells. The only way to maintain this is through the diffusion of water down the concentration gradient. So as soon as the salty water hits the blood stream, your body will move water from the interstitial space into the blood,   then water will move from the intracellular space into the interstitial space in order to equilibrate the concentration. This can have deleterious effects on your kidneys as it now needs to remove the excess salt by producing urine, which requires water. So it will further dehydrate you. Your body will also try to compensate from losing all these fluids by constricting your blood vessels to maintain blood pressure which is further damaging your body. Eventually you can go into organ failure, coma, and death.