I Have Broken Superficial Blood Vessels In My Feet, Behind My Knees, On My Chest And On My Thighs. What Is It?

Behind my  knee I have reddish area , about 2 inches across..I can see the vessels,they are bluish. It gets redder if I stand up.IF I touch the skin it goes white then back to reddish.  IF I elevate the knee it lightens just a little...whats going on?