I was scratching the back of my head, and a tiny, short, miniaturized looking, weak hair came off. I tend to get these on the top, as I've heard it's normal with AGA, but I've heard it's uncommon to have miniaturization on the back. Does this mean that if I ever start Minoxidil, I will have to apply it all over my head and not just on the top? (I've also read you should only use Minox on the top). Could it be something other than miniaturization? I seem to have some symptoms of hypothyroidism. Thanks.