VISA/MEDICAL RECORDS- ADVICE PLEASE!!

[scotsgirl]

myself, partner & kids are in very early stages of planning but hope in the future to move permenantly to Canada from the uk.  The thing thats worrying me is that my partner has a past history of drug use & while it is very much behind us now it is mentioned in his gp's medical records as he went to them for help.  So what I was wondering is will his gp be asked to provide a copy of his past medical records as part of the visa process???
Any advice would be greatly appreciated