I'm it's most severe case, HE is dibilitaing, it can cause you to forget who you are, talk to people that aren't there, stumbling and rambling. You just don't know what is going on an you can't make any sense.
This is a dangerous stage because you can also get extremely sleepy and it is possible to slip into a coma.
The symptoms can start as small as being a little confused, kind of fuzzy headed. Almost like that feeling you get when you have a cold and your ears and sinuses are clogged. Forgetting where you put things, putting things in strange places. Shaky hands, unable to complete a sentence (searching for your words).
For me, when I start to feel that foggy headed feeling, I immediately reach for the lactulose and it makes it go away.