I think they stop working propaly but I don't think it killes you
If you don't drink enough water, you could become dehydrated. This can result in many problems if it gets bad enough, such as your kidneys shutting down.
Your body is primarily made up of water and without the return of it from your kidneys you would become dehydrated.
you become dehydrated
Loss of weight
Constipation
They will die.
The dog will get dehydrated.
You need water and some rest
the kidneys clean it by removing the waste from the blood
When dehydrated, the kidneys and the liver work to protect themselves by adjusting their functions. The kidneys concentrate urine to conserve water in the body, while the liver focuses on metabolizing waste products efficiently. If dehydration persists, these organs may be at risk of damage.
It is because your kidneys are trying to remove the waste products from your blood but as the blood is quite thick from the dehydration the kidneys are having to work extra hard.
In a dehydrated person, the urine pH tends to be more acidic (pH below 7) due to the concentrated nature of the urine and increased reabsorption of bicarbonate in the kidneys. This happens as the body tries to conserve water by producing more concentrated urine.