Madhu Gopal, of Ilam School, asks :-
Why do our cheeks go red when we are embarrassed?
David Nicholls, a dermatologist with Canterbury Health, responded.
The skin of the face is full of numerous small blood vessels that can dilate (expand) and contract when acted on by impulses carried by nerves. For example, when we exercise hard our body heats up and the blood vessels expand to help cool us. Some people have higher than normal blood flows giving them a reddish complexion. Mostly the blood flow through the face is relatively constant but may be increased by hot food or drinks, alcohol, some drugs, heat, fever, some diseases and some thoughts.
Nerves travel from the part of the brain where it is believed that our thoughts originate. Our emotions spring directly from our thoughts. Although we may not wish it, we usually signal many of our thoughts and emotions in numerous ways, which may include stance, pos- ture, movements, size of the eye's pupil and so on. This is termed "body language", and is not hard to read by a knowledgeable person. Much is absorbed subconciously by those who meet us. Flushing of the face (reddened cheeks) is triggered through nervous impulses secondary to emotions such as embarrassment or shame, and can be seen as a form of body language or signalling. It is more common in young people who may be self-conscious, but often goes away with time.