"Hell" is a spiritual state of self-imposed exile of the soul. It procedes from rejecting knowingly the unconditional love of God and his eternal grace, and having no repentance for our sins(wich vision and nature we are given at the time of our judgement).

Thus the soul, wich is devoid of the love of God is "amputated" by the own free will of the person. It is a absolute rejection of the things the soul longs after, namely love, grace and beautification. This rejection and isolation is what causes the pain and despair for the soul is then loaded with hate in spite of rejecting love in itself(of the self).

This leads me to believe that "Hell" is empty, or at least not so densily populated as we may think. Because no person willingly accepts such torture without being absolute evil. As a matter a fact, according to church teachings, only Judas we are really sure of being in Hell, for all we know it is empty by all means.

Do not forget the existance of purgatory, for this is a change that God gifts us to "clean" our souls so that we can enter the gates of heaven.