O', what you have described there is injury. I never said that a papercut isn't an injury, but injury != torture. What you have just said implies that injury is torture. Now, I wouldn't like to get waterboarded, and I wouldn't like to get papercuts daily, but is that really qualified to be torture?

If my friend threw something at me and it hit my arm, resulting in a bruise, then that is not torture. However, it is injury.

It is true that current views on torture express ideas of extreme humiliation or extreme pain. That is torture. Small amounts of injury are not torture.

According to the UN Convention Against Torture, torture is:
" ...any act by which severe pain or suffering, whether physical or mental, is intentionally inflicted on a person for such purposes as obtaining from him, or a third person, information or a confession, punishing him for an act he or a third person has committed or is suspected of having committed, or intimidating or coercing him or a third person, or for any reason based on discrimination of any kind, when such pain or suffering is inflicted by or at the instigation of or with the consent or acquiescence of a public official or other person acting in an official capacity. It does not include pain or suffering arising only from, inherent in, or incidental to, lawful sanctions.
—UN Convention Against Torture

Notice in the beginning: "...severe pain or suffering, whether physical or mental, is intentionally inflicted on a person..."

Is a bit of water going up the nose "severe...suffering"?