Chinese medicals are very tough, but the Chinese airlines are trying to change that.
I have read, from numerous sources, for example, if you are over 50, and in PERFECT health you have a 50/50 chance of passing the medical.
Also, as described above, LOTS of false positive test results for all kinds of medical issues. Some guys were taking their medicals in various provinces, passing in some, failing in others...
I was offered a job in China, and I turned it down, partly because of the physical exam situation...