When my kidney's started to fail and they gave me steroids to try to stop the decay, my weight went from 176 to 214 pounds. I was at that weight for about 3 months, and it was a strain on my system and made it hard for me to eat. Well, since I had not really ate much in that time, and all of the weight on me was fluid, I unknowingly lost a lot of weight counterballanced by that fluid weight gain.
When I had my first dialysis treatment, which happend in the late afternoon in a hospital, the next morning after I woke up a strapping 140lbs. I lost 74 pounds in one night. I don't know how it happened, because you can normally only pull off so many Kilos in one treatment, but low and behold that was the result I experienced. I was given dialysis the next day too, but my weight loss from that was negligible.
Took me a while to get back up to my normal weight, but still remember that drastic weight loss, going from being big to tiny in one night.