When you go for your medicals, the clinic/doctor will ask you questions about your medical history. You will probably have to fill out a form. Don't lie, just tell them the truth. Everyone lies to their doctor, and so doctors are very good at figuring it out!
Neither of the conditions you mentioned will affect your application. Here's what affects your application
1. You have a condition that will cost more than $20,000 a year to treat. This would be some kind of serious/chronic illness. High cholesterol is not going to come close to costing $20,000 a year.
2. You have a very contagious/communicable disease that is a danger to public health in Canada (Active TB, etc).
3. You have a condition that makes you a danger to public safety (certain kinds of mental illnesses, psychosis etc)
If you don't have one of these three (and the two things you listed don't sound like that), your application will not be affected.