There is no such condition in Europe at all. SOME countries require a medical for a course but not many left (Malta is about it iirc). Nowhere else.
However just like anywhere else, a YES on the medical form means the instructor will need a medical document signed by a doctor certifying fitness to dive. Yes he could lie on the form, many people do but that gains nothing at all.
Go to a doctor, get the peace of mind of being declared healthy and then sign up providing that paperwork. Be open and honest about it.
