If you bought a refundable fare (unlikely) then you get a refund if you cancel. If you bought a non refundable fare (more usual) then you do not get a refund. Sometimes you will get a credit for future travel. Ask AA what the terms are on your ticket. Occasionally they will let you rebook to a later date for a medical emergency but there is no obligation to do so and I would not depend upon that. If you have insurance, that will pay provided you cancel for a covered reason, and you purchased enough insurance to cover the total cost of the flight. It’s normal for insurance to cover scenarios that you may not care about.

if you are concerned you should keep the insurance. To waive pre existing medical conditions you need to purchase within a small window from booking, typically 2 or 3 weeks, and cover the whole value of all non refundable expenditure.