Yes. A couple of times. Once I fell and injured my ankle. And the other was an infection (started as a flu) that went crazy and turned septic. I could hardly walk or even get out of bed.
I've had a couple close calls on falling when I was alone. I'm more careful than I used to be...particularly on the stairs. My worst experience was pushing something very heavy up the stairs and it got away from me sliding down the stairs so I hopped on it and rode down. Had I not it would have killed me at the bottom of the stairs.