Took my daughter to med center Wednesday night for a hurt foot. Dr thought it was fractured on her toe. Put a splint on it and wrapped it up. Went to ortho Friday and he said foot wasn't fractured. Took splint off and heel was bruised really bad. Then Friday night bruise was gone and then a HUGE blister appeared Saturday and has gotten bigger. Why did a blister form after the bruise and why do BIG?