The primary factor that influences health insurance premiums are the age of the policyholder—broadly speaking the amount of premium for the sum insured increases as you grow older. This is because as you get older, you are more prone to illnesses. The medical history of the policyholder is another important factor that will determine the medical health insurance premium. Lastly, the number of years the policyholder has not claimed insurance is taking into account while calculating the cost of the premium. These are the three main factors, all good medical insurance schemes consider while coming up with a competitive premium any policyholder.