Blushing is the reddening of a person's

face The face is the front of an animal's head that features the eyes, nose and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities may aff ...

due to

psychological Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries bet ...

reasons. It is normally involuntary and triggered by emotional

stress Stress may refer to: Science and medicine * Stress (biology), an organism's response to a stressor such as an environmental condition * Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...

associated with passion,

embarrassment Embarrassment or awkwardness is an emotional state that is associated with mild to severe levels of discomfort, and which is usually experienced when someone commits (or thinks of) a socially unacceptable or frowned-upon act that is witnessed ...

shyness Shyness (also called diffidence) is the feeling of apprehension, lack of comfort, or awkwardness especially when a person is around other people. This commonly occurs in new situations or with unfamiliar people; a shy person may simply opt ...

fear Fear is an intensely unpleasant emotion in response to perceiving or recognizing a danger or threat. Fear causes physiological changes that may produce behavioral reactions such as mounting an aggressive response or fleeing the threat. Fear ...

anger Anger, also known as wrath or rage, is an intense emotional state involving a strong uncomfortable and non-cooperative response to a perceived provocation, hurt or threat. A person experiencing anger will often experience physical effects, su ...

, or romantic stimulation. Severe blushing is common in people who have

social anxiety Social anxiety is the anxiety and fear specifically linked to being in social settings (i.e., interacting with others). Some categories of disorders associated with social anxiety include anxiety disorders, mood disorders, autism spectrum disor ...

in which the person experiences extreme and persistent

anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...

in social and performance situations.

Summary

Blushing is generally distinguished, despite a close physiological relation, from flushing, which is more intensive and extends over more of the body, and seldom has a mental source. If redness persists for abnormal amounts of time after blushing, then it may be considered an early sign of

rosacea Rosacea is a long-term skin condition that typically affects the face. It results in redness, pimples, swelling, and small and superficial dilated blood vessels. Often, the nose, cheeks, forehead, and chin are most involved. A red, enlarg ...

. Idiopathic craniofacial erythema is a medical condition where a person blushes strongly with little or no provocation. Just about any situation can bring on intense blushing and it may take one or two minutes for the blush to disappear. Severe blushing can make it difficult for the person to feel comfortable in either social or professional situations. People who have social phobia are particularly prone to idiopathic craniofacial erythema. Psychological treatments and medication can help control blushing. Some people are very sensitive to emotional stress. Given a stimulus such as embarrassment, the person's sympathetic nervous system will cause blood vessels to open wide, flooding the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

with

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

and resulting in reddening of the face. In some people, the ears, neck and upper chest may also blush. As well as causing redness, blushing can sometimes make the affected area feel hot. ''Erythrophobia'' is the fear of blushing, from grc, ερυθρός, , red and grc, φοβία, , fear literally "fear of redness".

Physiology

A blush is a reddening of the cheeks and forehead brought about by increased

capillary A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the bod ...

blood flow in the skin. It can also extend to the ears, neck and upper chest, an area termed the 'blush region'. There is evidence that the blushing region is anatomically different in structure. The facial skin, for example, has more capillary loops per unit area and generally more vessels per unit volume than other skin areas. In addition, blood vessels of the cheek are wider in diameter, are nearer the surface, and visibility is less diminished by tissue fluid. These specific characteristics of the architecture of the facial vessels led Wilkin in an overview of possible causes of facial flushing to the following conclusion: " ..increased capacity and greater visibility can account for the limited distribution of flushing". Evidence for special

vasodilation Vasodilation is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. The process is the opposite of vasoconstrictio ...

mechanisms was reported by Mellander and his colleagues (Mellander, Andersson, Afzelius, & Hellstrand. 1982). They studied buccal segments of the human facial veins

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called " test-tube experiments", these studies in biology a ...

. Unlike veins from other areas of the skin, facial veins responded with an active myogenic contraction to passive stretch and were therefore able to develop an intrinsic basal tone. Additionally Mellander et al. showed that the veins in this specific area were also supplied with beta-

adrenoceptor The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta ...

s in addition to the common alpha-adrenoceptors. These beta-adrenoceptors could exert a dilator mechanism on the above-described basal tone of the facial cutaneous

venous plexus In vertebrates, a venous plexus is a normal congregation anywhere in the body of multiple veins. A list of venous plexuses: * Basilar plexus * Batson venous plexus * Internal vertebral venous plexuses * Pterygoid plexus * Submucosal venous ple ...

. Mellander and his colleagues propose that this mechanism is involved in emotional blushing. Drummond has partially confirmed this effect by pharmacological blocking experiments (Drummond. 1997). In a number of trials, he blocked both alpha-

adrenergic receptor The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like bet ...

s (with phentolamine) and beta-adrenergic receptors (with propranolol introduced transcutaneously by iontophoresis). Blushing was measured at the forehead using a dual channel laser Doppler flowmeter. Subjects were undergraduate students divided into frequent and infrequent blushers according to self-report. Their mean age was 22.9 years, which is especially favorable for assessing blushing, since young subjects are more likely to blush and blush more intensively. The subjects underwent several procedures, one of which was designed to produce blushing. Alpha-adrenergic blockade with phentolamine had no influence on the amount of blushing in frequent or in infrequent blushers, indicating that release of sympathetic vasoconstrictor tone does not substantially influence blushing. This result was expected since vasoconstrictor tone in the facial area is known to be generally low (van der Meer. 1985). Beta-adrenergic blockade with propranolol on the other hand decreased blushing in both frequent and infrequent blushers. However, despite complete blockade, blood flow still increased substantially during the embarrassment and blushing inducing procedure. Additional vasodilator mechanisms must therefore be involved.

Psychology

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended ...

devoted Chapter 13 of his 1872 ''

The Expression of the Emotions in Man and Animals ''The Expression of the Emotions in Man and Animals'' is Charles Darwin's third major work of evolutionary theory, following ''On the Origin of Species'' (1859) and '' The Descent of Man'' (1871). Initially intended as a chapter in ''The Desce ...

'' to complex emotional states including self-attention, shame, shyness, modesty and blushing. He described blushing as "... the most peculiar and most human of all expressions." Several different psychological and psycho-physiological mechanisms for blushing have been hypothesized by Crozier (2010): "An explanation that emphasizes the blush's visibility proposes that when we feel shame we communicate our emotion to others and in doing so we send an important signal to them. It tells them something about us. It shows that we are ashamed or embarrassed, that we recognise that something is out of place. It shows that we are sorry about this. It shows that we want to put things right. To blush at innuendo is to show awareness of its implications and to display modesty that conveys that you are not brazen or shameless. The blush makes a particularly effective signal because it is involuntary and uncontrollable. Of course, a blush can be unwanted ut thecosts to the blusher on specific occasions are outweighed by the long-term benefits of being seen as adhering to the group and by the general advantages the blush provides: indeed the costs may enhance the signal's perceived value." A number of techniques may be used to help prevent or reduce blushing. It has also been suggested that blushing and flushing are the visible manifestations of the physiological rebound of the basic instinctual fight/flight mechanism, when physical action is not possible.Salzen, E. (2010), "Flushing and blushing" letter in ''The Psychologist'', Vol 23, No 7, July 2010, p. 539.

Summary

Physiology

Psychology

See also

References

Further reading