text: how do u know if there's a blood clot? my head slammed on the frame of a door (not the flat bit, the corner bit), and it left a huge lump on the left side of my forehead. (i was walking in the dark, tripped and free falled on my face)  3 days later, i notice a maroon spot, about the size of a red bean that's forming on the side of my left eye.  its located about 4cm away from the major lump area. anyone knows why's this? and what can i do about it? it's probably a bruise. a bruise is basically a clot of dead blood underneath your skin. it'll go away on it's own, but it never hurts to check with a doctor just in case....  by the way, if it is a blood clot, it's a superficial one, not the kind that can give you a heart attack or stroke. those are caused by blood clots that are inside the veins (called deep vein thrombosis). what you did was open up a blood vessel (popped it) so the clot formed outside of the circulatory system. it'll be absorbed back into your body, but it won't float around and screw things up.