Gua Ha in Chinese Medicine

Gua means like to hang? so maybe this came from the olden days before computers where maybe the numbers were hanging and oh my this is the thought, yeah de hao she number, right? mmm. If you go to a public hospital in china you kind of have to know this word gua ha because if you ask the staff there what do I do they will tell you you need to gua ha right or if you don't know where to register you might ask zainani gua haDe usually you will see a big plate that says gua ha show fake tool  and it's on the first floor of the hospitalright when you enter the hospital