system
Given the following post, respond as if you're commenting on Reddit:
human
How does the body build tolerance to caffeine?

In addition to building tolerance to its mental effects, how does the body become tolerant to its diuretic effects?
gpt
By regulation of the number of receptors sensitive to caffeine on the cell membrane.

Caffeine functions by inhibiting adenosine receptors in the brain, which we believe is involved in our biological clocks. After prolonged exposure to caffeine, the cell tries to return to homeostasis by *increasing* the number of adenosine receptors present on each cell's membrane to compensate for caffeine's effects. This results in the need for more caffeine to achieve the same effect on the brain as before, and can lead to withdrawal symptoms once the baseline caffeine level is removed.

Of course, there's more to it than that, but that's the crux of the idea.