This great question comes from Charlotte on Twitter!
That’s because of me!
Take two fingers and press them firmly (not too hard!) into your bicep, leg… anywhere, really! See how the skin gets lighter? That’s because the pressure you’re applying with your fingers is pushing the blood away from the surface of your skin. That’s also why the red seems to creep back to the area where you were pushing–you’re watching the blood flow back to that area. Pretty cool, huh?
Similarly, think of the last time you had sunburn. Have you ever wondered why you turn so red? This is because the blood rushes to the surface of your skin to begin working on repairing the damage done by the sun’s UV rays. This is also why, if you ever lay your hand on a fresh sunburn, the skin feels hot. The increased blood flow to the area means your body heat is being brought to the surface more quickly and intensely.
Here’s another example: give your cheeks a good pinch. See how, when you stop pinching, the area is red? It’s the same deal! The body senses that cells are being damaged, so it sends more blood to the area to repair the damage, making your skin red and warm to the touch.
Thanks for another great question! If you have a question for Dr. Smarty or one of his assistants, feel free to post them in the comments here!