Why Do You Blush?
The way you feel can affect your body. If you should feel ashamed or embarrassed about something, you might blush. When you blush, your brain sends signals to tiny blood vessels in your face and neck called capillaries. The signals cause the capillaries to swell with blood very quickly.
The extra blood brings heat with it, so your face and neck feel warm. If your skin is pale enough, the blood turns your face a bright red. You cannot control it. A blush happens by itself, whether you like it or not, but it also goes away by itself— usually in a few moments. While the psychology of blushing remains elusive, we do understand the physical process involved. Here’s how it works.
Blushing from embarrassment is governed by the same system that activates your fight-or-flight response: the sympathetic nervous system. This system is involuntary, meaning you don’t actually have to think to carry out the processes. In contrast, moving your arm is a voluntary action; You have to think about it, no matter how fleeting the thought is. This is good, because if moving your arm was involuntary, people would end up buying a lot of stuff they don’t want at auctions.
When you’re embarrassed, your body releases adrenaline. This hormone acts as a natural stimulant and has an array of effects on your body that are all part of the fight-or-flight response. Adrenaline speeds up your breathing and heart rate to prepare you to run from danger. It causes your pupils to grow bigger to allow you to take in as much visual information as possible. It slows down your digestive process so that the energy can be redirected to your muscles. All of these effects account for the jolt you feel when you find yourself embarrassed.
Adrenaline also causes your blood vessels to dilate (called vasodilation), in order to improve blood flow and oxygen delivery. This is the case with blushing. The veins in your face respond to a signal from the chemical transmitter adenylyl cyclase, which tells the veins to allow the adrenaline to do its magic. As a result, the veins in your face dilate, allowing more blood to flow through them than usual, creating the reddened appearance that tells others you’re embarrassed. In other words, adrenaline causes more local blood flow in your cheeks.
This sounds reasonable enough, but it’s interesting to note that this is an unusual response from your veins. Other types of blood vessels are responsive to adrenaline, but veins generally aren’t. In other regions of your body, veins don’t do much when adrenaline is released; the hormone has little or no effect on them.
Blushing from embarrassment is a unique phenomenon. There are other means by which our cheeks become flushed: Drinking alcohol or becoming sexually aroused can cause us to blush, but only being embarrassed causes the type of blushing that is triggered by adrenaline.
Some people opt to undergo surgery to limit their blushing response. Erythrophobia is the fear of blushing and it can be enough that it could lead to a person choosing to have the tiny nerves at his or her spine, which control blushing, snipped. This surgery — called endothoracic sympathectomy — has been shown to limit blushing.
Blushing is part of a powerful experience, but why have we developed this response to being embarrassed? Science hasn’t been able to answer that question definitively, regardless of what proves to be the ultimate explanation for why we blush, people seem to have developed an aptitude for forgiveness alongside their physical response to embarrassment — if we hadn’t, there’d be no reason for blushing. So the next time you suffer an awkward situation of your own making and feel your cheeks grow warm, just remember — this, too, shall pass.