Yes. It is probably in your insurance agreement that they have the right to share information related to your condition. More than likely, they forwarded this information for subrogation to recover money IF your injury/illness was caused by an accident. Basically the insurance company just wants to charge the person that caused the accident for your medical care so they dont lose money.
Usually when someone is in an accident, your medical coverage will not cover you and they will go after the person that caused the accident...thus the sharing of your information.

