What have you done wrong?
Or is your blush a sign of innocence?
Yes, I know that blushing is traditionally connected with guilt, but are you ever as likely to blush as when being given the once-over by customs officials?
But it's all right. There's no need to worry. All these people know that any serious criminal will have long surmounted the blushing problem.
Apart from guilt or innocence, a blush can be a sign of youth and health (that's what blusher is trying to convey) and, most of all, embarrassment.
But of course by far the commonest cause of blushing is a fear of blushing. A degree of this is normal. If it gets really out of hand it's called erythrophobia.
Mark Twain said that man is the only animal that blushes - or needs to; but in fact the Pharaoh hound (which is a rabbit-hunting dog from Malta):
blushes: its ears and nose go bright pink when excited.
Hmmm...I wonder if what we've always thought of as Rudolf the reindeer was actually an excited Pharaoh hound wearing high-altitude Sat Nav aerials?
Just a thought.
Thing Not To Do Today: blush. This word comes from the Old English blȳscan, and is related to blȳsian, to burn, and the Middle Low German blüsen to light a fire.