...when I get attention.

It happens when I'm put 'on the spot' or just questioned about something in front of people. I go really red in the face. If anyone notices and points it out, it gets worse and I want to leave.

It's not something I can control, it would seem. 

My close mates are aware of it and divert attention away from me if it happens.

I'm not shy.

But sometimes I get anxious before I go to meet a group of people, on my way to a dinner for example, and actually consider not going. I don't really like talking about myself, even though I have plenty of conversation within. I'm most relaxed when talking to just one or two people. Any more than that and I struggle, unless I know them. Even if I do it can be difficult.

Anyone else have this?

The unintentional blush (or tomato face is how lots of people used to call me) is the most off putting thing and it makes you think twice before saying anything, whether it be in a class or just with a group of people and, as you say, even sometimes with friends. I think it just has something to do with confidence. Already to have the confidence to speak up is hard, and then once the attention is focused on you, you're not sure whether what you are going to say is right or sounds stupid, or whether it is funny or inconsequential etc...Just think that you are allowed to talk just as much as everyone else and that whatever you may say, even if you think it might sound silly, has some value and is what makes you present. I think it is also one of those things where the more you accept it the less it becomes an issue.

I also get the anxious feeling when I go out and I feel more comfortable with smaller groups of people. But I still haven't found a solution to that. I feel I can't get to know someone unless I talk to them individually. Anyone have any advice?

i feel a little strange contributing to this talkabout given my username. I don't have a problem with blushing but i am very conscious of when other people do - i always feel like i have offended them - or that they are very sensitive. i think it is helpful to comment or say why you blush - as it makes people like me feel more comfortable that they have not offended you or something.