Health insurance premiums are calculated on the basis of age, taking the age of the elder member into consideration. The premiums increase steeply once you cross 55-60 years of age due to the high claims ratio in that age group. To maintain the loss ratio insurance companies charge high premium from the customers and this increases the health insurance premium. It is not advisable to include parents in your health insurance policy as the premium would increase steeply. For better premiums, two policies can be taken; one for family and the other for parents.