Do I need health check in UK for work visa

I am currently in China on a business entry permit, my company is applying for a work Z for me to stay 1 year + . I have been told to get the medical check done here in China, but the website says I also need a health certificate from 'overseas country' ie the UK. Is this going to be a problem if I don't have this. It's not clear if this is a hard requirement.