@Flyfrequently can’t really answer these questions for you. It totally depends on the particular card insurance you have, the particular medical conditions you gave (noting that usually anything at all that you’ve seen a doctor for in the past 12 months at the time of applying is regarded as a pre-existing condition), your age, the length of your trip, how long between when
You take the insurance and when the trip starts, and other factors known only by the insurers.
You will need to call your proposed insurer and ask them - or fill in the web site quote forms and see what they tell you. Fred credit card insurance usually charges a fee around $75 just to assess your medical conditions and may also then charge you an extra premium depending on the factors above. Good luck! It’s a bit of a mine field until you get more experience with it.