Matia,
The pain scale that is most commonly used by docs
is the Mankoski (or Mankowski) pain scale.
If I can find it in my files, I'll copy and paste it.
But.... that is the one where a 10 is unconsciousness,
9 is excruciating with constant migraines of an unbearable level,
and so on down the line. Most who claim to be at a 10 level,
who aren't really aware of this scale, are probably at
a 7 or 8 on the Mankoski scale.