Can my employer see my health information?
Health information is generally considered to be sensitive personal information. Your employer cannot ask your doctor to provide medical information, unless you agree to it.
There may be some cases where it's important for your employer to be provided with more detailed health information, or even have the opportunity to discuss matters with your doctor. For example, if your employer is managing your return to work after a workplace injury, they may need to be able to speak with your doctor, with your knowledge and permission, in order to establish what work you can or cannot do.
If your employer asks for health information about you that extends beyond requesting a medical certificate to explain a period of sickness, you may want to get some employment law advice and/or contact your doctor to discuss any concerns you may have about the request.