I read the whole article and still didn't know what it was until I web searched.  I would have listened more to what was written, but I was too busy looking for what hypoalgesia was, so the actual content was lost on me.  I even performed a document word search, in case it was defined and I'd missed it in, but there are 6 occurrences and no definitions.   Wikipedia told me this: Hypoalgesia or hypalgesia denotes a decreased sensitivity to painful stimuli...   of course I could glean this as implied from the many paragraphs in the article, but the burden for finding such things shouldn't be placed on the reader unless it's a mystery or a puzzle and intentionally obscure.

Sincerely, a disappointed curmudgeon.