Insurance policies that cover a single disease like cancer or heart ailment are becoming popular, given the high incidence rates of these ailments and the ensuing expensive treatment. These are seen to be replacing critical illness policies which were, typically, used to enhance the cover of a person who already had a standard health insurance policy. A critical illness policy pays a fixed sum if the policyholder suffers from one of the 20-30 specified diseases, including cancer and kidney failure. Neil Borate asks experts how to choose between a critical illness plan and a disease-specific insurance policy