Lily,
HIPPA allows a doctor or medical person to give private knowledge to another medical person IF it pertains to your treatment. For that there is no authorization needed. HIPPA does not allow your doctor or any medical person to discuss your illness with anyone else without you permission. Listing you illness in a hospital record is allowed as that is a record of your treatment and if you need a followup that would be of interest to the next doctor.
Newfie11