The individual health insurance premium is calculated based on the sum insured you have chosen and your age. The premium will increase based on the age of slabs according to the premium chart of the insurance company. In case of PSU companies such as National Insurance, The New India Assurance, The Oriental Insurance and United India Insurance the premium can increase without a change in age slab if the person has taken claim in the last year. They charge loading on it and thus your premium will increase.