The bills can run up very quickly. In about 2014 (can't remember exactly), OH who is type 1 diabetic quickly developed a cough/chest infection overnight. At home we would have expected her doctor to offer a course of antibiotics, but as it was a 'sea day', we went down to the Medical room, on the Majesty, expecting something similar.
She received several tests, and a coupe of 'one hour drip sessions', administered by the nurse, to help her recover more quickly, but meanwhile could continue her cruise as normal. They reassured me not to worry (about the bill that was), as they would contact the insurance, once I gave them the details.
At the end of the cruise, our on-board account only had the 'insurance excess' added, as treatment had been cleared by LV - all £1800 worth.
Following month, OH attends diabetic appointment at hospital, and took the detailed bill along in case it had any relevance to her condition. Quote from consultant - 'Did they really do all this'?