My husband has dementia due to blood loss causing a lack of oxygen to the brain. He is very aware of his issues. The only emotion he has anymore is anger which is normally due to frustration. Though he forgets what he is mad about, the emotion (the anger) seems to last for hours, even days. When asked why he's angry he says he isn't but he won't speak and has a scowl on his face. He was never angry in his healthy life and there is no hidden illness masquerading as anger.