I tend to buy medical insurance most of the time especially if the tickets were expensive. I did have to make a claim once and although I had a valid reason with my doctors signature I was surprised at some of the questions on the form as I filled it out. I think one of the questions for the doctor was "have you treated this patient for this condition in the past year", evidently if you have a pre-existing condition or something you have been treated for in the past they can refuse to pay out. For myself I had a bad attack of diverticulitis which made it impossible to fly but thankfully had not had an attack for a few years. I would be very careful to read the small print if I had conditions like diabetes, heart problems etc.