What would cause this erratic behavior in an elderly person?
My wife's grandfather is living with us. He's just not able to care for himself since his wife died. So we're looking after him. His behavior is growing more erratic all the time. Mostly anger. He also sits in the corner and just talks to himself all day long. He will have conversation with people that aren't even in the room. One day he even proceeded to give someone a tour of the house. "Hey how ya doin' let me show you around". And he went from room to room telling this person stories about the stuff in the room. But. he was alone. Nobody was with him. He does this kind of stuff all the time. But the main problem is the anger. It comes out of nowhere. This morning he wanted to cook some bacon. ok no problem. I asked him 4 times if he wanted help with it. He insisted he did not. So i go sit at the table. two mins later he comes over with the bacon, throws the plate of bacon at me and calls me an *** for just sitting there. What the heck? A few days ago he did something similar to the dog. He tried to give the dog a biscuit. The dog clearly didn't want it. So he shoves the treat in the dog's face and says "Take it you stupid asshole" and then kicks the dog. The people next door just put their house up for sale. He's now looking for ways "to get even" with them as he says. He says "he can't believe someone would do that. That's very rude". So he wants to "get even" he says. Why would a person act like this? It's clearly not normal. Is it just old age? Or should we worry?