Blushing is a nervous reaction that triggers tiny blood vessels in your skin to widen. This allows more blood to flow to your skin and creates that reddening effect that you seem to know all too well. Blushing just happens to be your way of reacting to a particular situation. Someone else may not visibly blush, but they may very noisily tap their fingers or clear their throat. Everybody is different, but everybody gets embarrassed or nervous sometimes!