what could this be?

[stressyBessy22]

Not parent, but 71 yr old relative.
all consuming exhaustion ,skeletally thin, 'forgetting about eating and drinking, losing teeth, funny sickeningly sweet smell about them, slight yellowing of eyes.
Described like this by neighbour who found her collapsed .She is in hospital and we are waiting for news.
I fear she may be riddled with cancer

all sorts especially if not been eating or drinking well, don't jump to conclusions.

This doesn't sound good. The sweet smell could possibly be badly controlled diabetes. She may have kidney failure (the exhaustion, forgetfulness) and of course she may have cancer but there's not much point speculating. I hope she's getting good care in hospital.