How much urine is poison?

I have heard that holding in your pee can kill you. How long would you have to not urinate, or how much actual urine witheld in the bladder would it take to kill a person? Also, what is it in urine that is toxic? Does urine makeup vary? Oh, and on a more disgusting note, is it possible to die from ingesting urine, barring any diseases the “creator” of the urine might have?

For part 1, the reason holding in your pee can kill you is not that
it’s poisonous but that it will rupture your bladder which is often
fatal (Tycho Brahe died that way).

For part 2, yes it is definitely possible to die from ingesting
urine. Urea and ammonia are both toxins.

IIRC, urine doesn’t contain ammonia as your liver converts it into urea.

I understand now. Is urea in fact a toxin though? I wouldn’t think something your body made would be, but then again many things your body does kill you in the end, for instance autoimmune disorders. Thanks again guys.

Cecil briefly discusses drinking urine at the bottom of this column.

Well, yes, that’s why we excrete it. Urea is created by the metabolism of compounds containing nitrogen, mainly proteins. It is toxic to cells, so they dump it into the blood stream where it can be filtered out by the kidneys and flushed out of the body.

Unless the pee’er has an infection, then urine is ok IIRC. If you drank too much? Probably throw up.