Your stomach lining turns red when you blush, a response that is the result of the sympathetic nervous system causing increased blood flow throughout the body. During periods of embarrassment, the body releases adrenaline, a hormone that prepares the body for stressful situations. Adrenaline also makes the blood vessels dilate in order to improve blood flow and oxygen delivery in case the body has to suddenly flee a dangerous situation. The veins in the face, as well as in the stomach lining and throughout the rest of the body, then have more blood than normal flowing through them, and they appear red.
More about blushing:
- A surgery known as endothoracic sympathectomy can potentially eliminate blushing by snipping the small nerves located in the spine that trigger the response.
- Naturalist Charles Darwin, best known for his theory of evolution, was among the first to study blushing and claimed the act was one of the only mechanisms that is a distinctly human behavior.
- One study found that people who blushed were viewed to be more likable and judged less harshly for negative behavior.