What kind of jobs require a medical certification?

Here's the general practice here:

After you've passed interviews for a job, your potential employer would ask for several clearances: police clearance, barangay clearance, NBI clearance, etc.  These you will have to pay for.

After you've done that, the employer will ask you to get a medical certification.  Usually, it's the employer who foots the bill.  The employer might give you a stub, and have you go to one of their accredited clinics. 

In the US, it might be considered an invasion of privacy to take medical testing for regular office day jobs.  But here, if your employer asks for it, you'd have to provide it.  My husband's employer required x-ray, urine, fecal, and blood samples, plus a hernia test.  He's not applying for the military or in the medical field.  It's for a call center company.