This question has been asked and answered so many times, we could probably write a book about it. But the answer is surprisingly simple: Your body produces adrenaline when you’re in danger or stressed. When stress hits your adrenal glands (the small, round organs that sit just below the kidneys), they respond by releasing hormones into your bloodstream that tell your blood vessels to contract and allow more blood to rush to your face. This causes redness of the skin as well as increased sweating, which often leads to “hot flashes.”
The good news is that if these symptoms are new or haven’t responded to treatment for some time, then they likely indicate an underlying medical condition that needs treatment first. So don’t sweat testing on yourself — go see a doctor!