Why do they always say condition is far worse than the reality?

I have been visiting a sick relative for months now. When I first arrived another family member, someone very "smart" and college educated, told me things that sounded so bad but were in fact not the reality at all. For example, they said that "Soon, within weeks, they (the patient) won't ever be able to walk again." Well, they have been walking fine for months now. I spoke with a doctor at the facility who told me that wasn't the case at all and the patient should be able to walk for the foreseeable future to possibly many years in the future. Recently, this same family member told me that they (the patient) now has a serious type of condition. I didn't think so, and didn't argue, and asked a nurse who told me that they did not have the condition at all.

So what goes on here? Why do they say things that are far worse or serious things that don't even exist? Has anyone else experienced this phenomenon? Is it psychological or just dumb?