Why is this happening to my boyfriend (health issues, disorientation, please rea!

Ever since yesterday morning, my boyfriend has been sort of disoriented. Yesterday when I was with him - at times - he would just stare blankly at a wall or at me, for like 5 minutes and then you'd have to do or say something to him to get him to snap out of it. Then afterwards he said that when that happens, everything just seems surreal to him and he almost didn't know where he was. The same thing happened today. He said that he's been fairly numb to pain, but not completely numb to it. Last night, he said that he would wake up scared from a nightmare, and - at first - not know where he was. He was driving to my house this morning and he told me that on his way to my house, he would occasionally zone out and then during that time - again - not know where he was. Today, he was walking with me and he'd stay really close by me, so that if he zoned out and didn't know where he was, that he wouldn't get all freaked out. He also said that he would kind of get tunnel vision at some points during the day.

I thought about it and thought that he might be feeling this way because of lack of sleep, but he usually gets decent sleep hours.. And I never feel the way he's describing to me, even when I stay up 24 hours (I've only stayed up that long once or twice in the past).

Anyways, other than lack of sleep, does anyone have any other opinions as to what could be going on?
I care a lot about him and I'd rather be safe than sorry.. So opinions are much appreciated. (: