Hi Illegal, first of all it sounds like you can do with some hugs, so some coming your way:
But then depending on the situation maybe you are going to have to ask someone/people. Kind of the same way as if you're feeling down, some people might be perceptive/notice, others may not, or some may not know how to help, or may not know how much a hug might mean to you. Doesn't mean that some people might not be more than ready to give you a hug if you need/want one though.
And just like TrueMe said, there's nothing wrong with asking for a hug.
In general though maybe you can mention to people that it might be good if you could hug more or ask why you/they don't???
Or depending on the person/people, even try to be a bit more spontaneous about that yourself??? And it might become a bit more "second nature" in those relationships at times???
Alison