Can physical infirmity be a catalyst for unrelated negative thoughts?

I have a current illness that makes me physically uncomfortable fairly often. At the same time, I feel like I have an influx of UNRELATED but unhappy thoughts. I can wake up in the morning, with no precipitating thought/event, seemingly out of no where I start thinking over and over about negative things. Is there a connection between the physical pain I feel and, for example, recalling the mean thing someone said to me in childhood? Then contemplating my pet peeves? Any opinions would be great (no insults please).