New Delhi, Oct. 13 -- It's common knowledge that when you buy a health insurance plan, it's renewable for life. But did you know health insurance rules prohibit insurers from increasing the premium based on changes to your health upon renewal? This rule is meant to prevent ageing and ailing policyholders from being singled out and penalised (though it doesn't stop insurers from increasing premiums at the overall level).

However, a growing number of insurers seem to be ignoring this rule by asking customers to disclose their health status at the time of renewal, with the caveat that "any material change can alter the scope of coverage or premium at renewal if a policyholder discloses a major change in health condition". While asking polic...