Even mild dehydration can 'shrink' your brain: Here's what you should do to prevent it

The brain is about 75% water, so it is very sensitive to changes in hydration. When a person does not drink enough water, the concentration of salts and other substances in the blood goes up (this is called increased serum osmolality). The body controls this process through brain cell water release which causes brain cells to shrink.

Even mild dehydration can 'shrink' your brain: Here's what you should do to prevent it
The brain is about 75% water, so it is very sensitive to changes in hydration. When a person does not drink enough water, the concentration of salts and other substances in the blood goes up (this is called increased serum osmolality). The body controls this process through brain cell water release which causes brain cells to shrink.