As John Bradshaw says, toxic shame causes a person to go into hiding. He/she hides their emotions ... their thoughts ... their feelings ... they try to hide their humanity – in which they try to hide that they are sexual, that they have emotions, that they have bodily functions, that they are imperfect beings. They hide their perceived imperfections because they fear their "flaws" (and thus their perceived unworthiness as a person) will be exposed. And, so, those with toxic shame tend to live in secretiveness.
I think this is one of the best descriptions of SA that I've read, at least as far as it applies to me. I know every time that I let someone know how I feel or what I think is a tiny victory -- something I had much more trouble doing when I was younger. I still have nightmares, though, about this kind of shame, where all my secrets are in a little cardboard box and then someone finds them. I'm hoping some day I can have that dream and go "So what?" when that box is opened.
"They had to laugh, otherwise it would be too terrifying." -Bukowski