Blushing happens when blood rushes to the capillaries near the surface of the face and neck, causing a reddening of the skin in those areas. Physiologically, this process helps regulate your body temperature as more blood near the surface means more heat loss. Why this happens when we feel embarrassed or uncomfortable isn't fully understood, though we've all been through it. If you're concerned about whether or not you're blushing, check for the following signs.
Check physical sensations. Does your face feel hot? How about your ears, forehead or neck? Although it's actually cooling you down, the extra blood will make that portion of your body seem warmer than usual. Some people also feel a tightness in the skin of their forearms and hands when they blush. This is caused because the blood going to your head is coming from your extremities. This is also happening to your legs and feet, but our hands and forearms are the most sensitive.
Watch peoples' reactions. Blushing is very noticeable, and you may be able to tell something's up by how people act around you. If you're lucky, others may actually start to blush because they saw you start to blush (blushing can be like yawning that way). A nice alternative, of course, is to ask a friend or other bystander. Most people will answer truthfully. If you're anxious or embarrassed about blushing, try making a joke out of it. Passing things off lightly can make the whole thing less traumatic for you.
Look in a mirror. Is your face red? How about your neck or ears? If the answer is yes, that's pretty much the definition of blushing.