Pain Necessary to Know is the third studio album by the Italian avant-garde metal band Ephel Duath. The album was observed to be another departure for the band, with Ciaran Tracey noting in Terrorizer that "its sheer difference in the hugely tangential path Ephel Duath have taken from everything done hitherto, even in terms of their own varied and colourful palette". Tracey further observed that the band's previous "multiple personality disorder seems to have been replaced by a bipolar schizophrenia, with the numerous faces of past work having been cast aside in favour of two basic protagonists: explosive rage and light jazz".