Not from me, anyway, though that's a purely personal thing. The human body is actually pretty good at replacing lost blood, and people nick and scrape themselves all the time---and bruise, bruise too. Just a sec.

[Sam shifts about to present her shin to the camera. There's a brightly-coloured bruise there, highly visible in spite of her tattoos.]

Banged it hard enough to break some of the smallest blood vessels, but without a break in the skin, it's just trapped in that area until it's healed up. No big, but high-volume blood loss, that's a bad scene. And the reason we have blood donation, which you'll probably find pretty interesting.