You have heard about disclaimers, right?
You know, like the ones about epilepsy that show up in every single game manual? Or all the warnings that Nintendo give you on the Wii (take a break, wear the strap, wash your hands, brush your teeth)?
Nintendo are not going to diagnose anything. At most they will deliver medical data to your hospital or doctor of choice. They are not replacing doctors or the medical industry. They will still warn you that "Wii Health is in no way a substitute for regular checkups, and if you feel sick, please contact a doctor immediately (like Skype warns you that their service is no substitute for traditional phones so don't count on it in an emergency; that's also legal speak for "don't come looking for us if your child died because you used Skype to call for an ambulance").
Good luck suing Nintendo, because you'd be a fool to think they, or any company, would in their right mind expose themselves to such litigious possibilities.
Essay Pro