Have to reschedule an interview because I almost died in surgery. What do I say to the recruiter?

TLDR: I had a tonsillectomy over the previous weekend and was fully expecting to be fine by the time of my interview. A week later I ended up having a massive arterial hemorrhage and am now on bed rest for the rest of the week and can’t speak.

I don’t want the recruiter to think I’m flaky so do I let them know that I had a surgical complication or do I leave that part out and just ask to reschedule?