I think an uncomfortable silence occurs when someone says something that seems outrageous or unthinkable or in some way offends others. I once did this when everyone in the room was talking about what they used to do in the early 1960s. I blurted out (without thinking) that I was in kindergarten during that time. Everyone just stopped mid sentence and stared at me! The room was so silent you could have dropped a pin on the floor and everyone in it would have heard that pin drop. They all were staring at me as if I were an alien.
My statement made them feel OLD. It made them think of me as a baby, although I was in my mid twenties at that time. Finally the hostess changed the subject and the party went on as if nothing had happened.
I use this example to show you the kind of thing that would cause an uncomfortable silence. If you have not said anything alarming or unnerving, chances are that a silence is just a natural thing in a conversation. Silences are normal, folks need to think up something new to talk about. Folks give their breath and their mouth a rest for a bit, or they might just be thinking upon something someone said, but not aghast or upset by that something.
If you feel really upset by a silence, say excuse me, get up and go use the bathroom or if you are in someone's house, and they are in the kitchen, ask them if they need any help by going into the kitchen to see if there is something you can help them with. Whoever is in the kitchen rarely objects to being helped. You could set the table for them, or bring something from the kitchen into the place where guests are being entertained. You could also grab a photo album or book from the coffee table and browse through it, occupying yourself in some way in other words.
