because the medical is ridiculous, get used to it, i just had bad blood results, more test etc, they test for everything including HIV so anything out of the ordinary is treated like the plague, pretty much all our guys get stuff at some time, high BP and kidney stones are a favourite and its treated by having a month off(no pay), then if you come back with ok results and have to take another month off before coming back to work(no pay). you will find out when you do your initial medical, if theres anything wrong they will find it, if theres nothing wrong, they test until they find something wrong
all of the limits for bloods etc have been decreased as well now so its even harder but this is not the companies fault, its a CAAC run hospital