My whole life I've taken on more roles in front of an audience than most Swedes, even though it's never been part of my profession. I've taken theater classes, been on radio, been a teaching assistant, led games at summer camps, led a Swedish speaking group for immigrants, and in the last year I've started holding lunch lectures - brown bags - at work, and a couple of weeks ago I started a university course in rhetoric.
In these situations, I sometimes feel stage fright, of which there seems to be two kinds that I'm affected by: during preparation and on stage. Nowadays, I'm able to mostly ignore these feelings, even though my heart rate increases.
If I need to perform in front of an audience, how I feel mostly depends on whether I know what I'm going to say. Before I'm satisfied with my preparations, I tend to get tense, especially if I'm going to perform in a new situation. Perhaps this tenseness also encourages me to actually prepare something.
I never know beforehand whether I'll be nervous on stage, although it's more likely when performing in front of an audience of people I don't know. During a performance, my stage fright is expressed by basically all my muscles making miniscule vibrations, and by a highly elevated heart rate.
For some reason, it seems like nobody is able to detect my body and voice shaking. Except my sister, who knows me well and is extremely perceptive.