BUMPs are used to allow people affected with blindness to consume literature or read various things that we take for granted in day to day life, including drive-in ATMs in America?! These BUMPs are called "braille"
BUMPs on the head, otherwise known as scalp hematomas, are caused when blood vessels burst under the surface of the skin and the ensuing clots raise the skin at the site of some type of injury.