The law protects your medical history and communications back and forth with your care providers. In a litigation case for example, unless you sign a HIPPA release to allow an opposing lawyer to obtain such records, they are not avialable for access.
Check with a lawyer in your locale for any specific rules that might apply.
Good luck to you.
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I am not licensed to practice law in Michigan so the following should not be taken as legal advice, but simply as information based on general principles of law which is intended to educate. If you need legal advice, please consult a lawyer who holds Michigan licensure.
If you have brought a lawsuit, such as a lawsuit for personal injury, in which you place your medical condition at issue, you must produce the records relevant to your claim or your claim will be dismissed. In such a circumstance you are said to have "waived" the physician-patient privilege, which normally applies to statements made to a medical professional for purposes of diagnosis or treatment, by bringing the lawsuit.
But outside of that circumstance, your medical records are, generally speaking, private and protected both by privilege and by HIPAA. WHY is this lawyer demanding to see your medical records? Usually the demand is in the context of a lawsuit. If you brought the suit, and it's because you claim to have been injured, then yes, the lawyer can get your medical records, i.e., you HAVE to consent, or your suit will be dismissed. You don't say one way or the other whether this is the circumstance, so it's impossible to speak to your specific situation.