What is a Blush?

Abstract

Darwin was aware that the redness of the face, ears, neck and upper chest — the ‘blush region’ — is due to increased blood flow in that region brought about by vasodilation of the capillaries lying just under the skin. The mechanism responsible for this reddening was not understood at the time and while we now know a great deal more about the cardiovascular system and have learnt a little more about the physiology of the blush, the process remains mysterious. The blush is rarely discussed in textbooks of the cardiovascular system and if it is mentioned, it is typically to acknowledge how little it is understood. This chapter locates the blush within the context of what is known about the system and considers explanations that have been proposed. The final section examines measurement issues.