Earlier coverage for critical illnesses such as Cancer, AIDS, and Heart Attack etc. was not offered by any health insurance plan. But, today, things have changed a lot in the health insurance sector. Today, health insurance companies like Apollo Munich tend to offer critical illness cover under a rider option, which one can take with any given plan at an additional cost. However, when opting for a critical illness cover, it is of utmost importance that one goes through its terms and conditions, so as to avoid any coverage issues later on. After all, it is best to be sure of the kind of coverage being offered especially when you are opting for a critical illness plan.