There are certain jobs in Canada with a pre-condition that the applicant must undergo a medical check before applying. This would apply to those people also whose country is not mentioned in the designated list of countries exempted from a medical exam.
These jobs are of the nature where an individual would require working in an environment where medical fitness is a pre-requisite. For instance, the jobs as a medical practitioner, agricultural worker, caregiver for elders or children, or as teacher etc would require you to prove your medical fitness.
In case you wish to work in one of these fields while already in Canada but do not have a medical exam, you can apply for it while in Canada. You can start working as soon as your application for the change in work permit is approved.
What establishes your Medical Fitness?
You can be declared as medically unfit for immigration to Canada if (i) you suffer from any chronic disease that might affect the health of other Canadian nationals and threaten them in some way, or (ii) if you suffer from an ailment, disease or health problem that might make Canadian health services unnecessarily burdened due to your health condition. However, if you have a sponsor who is ready to take your financial responsibility, any such situation can be overlooked.
A number of factors are crucial in deciding if a person can be admitted immigrating to Canada despite a health condition. The duration of the ailment, its nature, treatment and the strain the health condition would cause on Canadian health services and social services remains an important consideration in determining if he/she can be permitted a permanent residency in the country.